The standard lengths of the Old Town lines are listed at http://forums.wcha.org/attachment.php?attachmentid=1064&d=1136757320 and the sailing kits usually shipped unassembled so there wasn't a standard rigging for the lines. The images below show how I usually run the lines but there are many other good solutions. Let me know if this doesn't answer your question,
This is close to what I was going to do. Wanted to check first, as this customer is pretty fusy about things being correct...
Only change I was going to make on this sixteen footer was running the sheet line from the stern seat, though two blocks on the boom, to a block on the LBT then back to the sailor...What do you think, am I going too crazy with the three blocks? Or reverrse that and put the downside block attached to the seat, and just end the front of the line on the LBT?
No, you aren't crazy. You're actually on track toward a system that works much better than the typical mid-boom sheeting. The halyard on a lateen doesn't really matter much. It can be run either fore and aft through the masthead or crosswise through it. If you want to tie it off at the base of the mast or bring it back to a place like the leeboard bracket where it's easier to reach, either will work just fine. The mainsheet is a different story. If you use the typical mid-boom sheeting (tie the sheet to the middle of the boom and lead it down to the "cockpit") the first thing that mainsheet tension will do is to bend the light and rather flexible boom that most lateens have. This has a tendency to quickly match the boom's shape to the foot round of the sail and any more tension usually starts pulling the intended draft out of the sail. Under higher tension, it will also distort the shape of the entire sail.
There are indeed times when you want the tension to flatten the sail, but not so early, or in light air. Ideally, you should be able to sail in reasonably hefty winds without distorting the boom or the sail's foot, or losing your draft. Then when you do turn upwind and sail close-hauled (pretty much sheeted in about as much as you can) or if the wind really picks up and you're getting overpowered, increasing the sheet tension even more for those conditions will start to flatten the sail for better performance. While being easy to rig, mid-boom sheeting on a lateen just isn't very effective because it usually can't do this, and combating excessive yard and boom bend due to thin, long spars is one of the biggest problems in getting a canoe lateen sail to really work well.
A sheeting system that has drastically better performance on lateen sails over a broad range of conditions is shown in the drawing here. We start with the aft end of the sheet tied off at the stern or even better, to a cross-wise rope traveler or bridle where the sheet's aft end has a ring or block on it that can slide gunwale to gunwale along the bridle. The sheet then leads up to a boom block fairly far aft on the boom and then forward along the underside of the boom. Some boats will add a small fairlead mid boom to help control the sheet drooping when tacking, but it doesn't put any tension on the middle of the boom that would induce bend. The sheet then proceeds forward along the boom to another boom block, just aft of the mast (farther forward than the lee board bracket). From there, it drops down to a third block either attached to the back of the mast or to the mast thwart or mast seat and finally, it heads aft to the sailor. He can either hand-hold it or have a quick-release cleat back there (open clam-cleat or a cam-cleat) to give his hand a rest.
While maybe sounding awfully complex, this system has a few major advantages. First, it does not pull down on the middle of the boom causing excessive boom bend and sail distortion. Secondly, as is does pull down as you tighten the sheet, or pull down less as you ease the sheet, it forms an automatic, self-adjusting downhaul that's pulling on your sail in places where sails should be pulled on. Sheeting in hard for upwind beats or in high-wind conditions increases the tension along the front of the sail and reduces the draft (due to the forward boom block's position) and flattens the sail properly. Your boat points higher and is less likely to be overpowered. Easing the sheet to sail off the wind automatically eases this downhaul tension, increasing your sail's draft, which is what you want to happen on those points of sail. Thirdly when sailing in high winds with high mainsheet tension pulling back at you, this tension is tending to pull you down into the boat. A mid-boom sheet, hanging down from the boom under high tension is trying to pull you out of the boat.
This improved method of sheeting a lateen is not new. In fact, it is the system that has been used on thousands of Sunfish sailboats and similar boats over decades because it works really well. If it has any drawback, it would be the drooping sheet under the boom when you tack and take the pressure off of it. It can hang up on your lifejacket. You pretty quickly learn this and how to deal with it. The easiest method is simply to wait as you tack until the sail goes limp, grab both the boom and sheet in one hand and just pass it over your head. There is usually no reason in a sailing canoe to be hunkered down during a tack watching a wiggling boom and waiting for it to cross over. Your tacks will be faster and much more efficient to just wait for that slack period and take the cross-over situation into your own hands.
Anyway, this is how the ideal situation looks. This one has the rope bridle across the stern. The aft end of the mainsheet has a ring that can slide along the bridle. Notice how close the forward boom block is to the mast. This provides the all-important downhaul tension, pulling the boom down near the luff. The lower block can be tied to the mast, tied to the seat frame, or attached with a fitting of some sort, and the mainsheet then runs back to the sailor.
The later Old Town sailing rigs like the Wahoo used three blocks as shown below but without the downhaul and other benefits described in Todd's message. Please post some pictures when you put it all together and let us know how the customer likes it in use. Thanks,