Aside from the question of whether you want an “authentic” restoration, whether to restore a keel or to leave it off depends in good part on how you intend to use the canoe, and very much on personal taste.
A keel will provide some protection to the bottom, some stiffness to the hull, and some directional stability. It will add a little bit of weight, and may make a canoe a bit less maneuverable. So - - -
If you will be free-style canoeing, or paddling a lot of white water where maximum maneuverability is needed, you don’t want a keel.
If your canoe will be your lakeside summer camp utility boat, used by kids and visitors who may not always be attentive to the care a w/c canoe should get, you may want the protection of a keel.
If you will be paddling or cruising on lakes and flat water rivers, especially if they are windy, you may like the directional stability given by a keel, and if you plan to sail the canoe, you will want a keel.
The length of the canoe and the shape of its hull should be considered – cruising in a flat-bottomed short canoe (15’ or less) with a keel is easier because of the added directional stability, whereas a longer canoe (18’ and up), especially if it has a shallow-arched or rounded hull bottom, will tend to go straighter even without a keel.
Virtually all of our paddling is done on flat water – streams, rivers, and lakes. Windy conditions are common. I find that our 15’ Old Town 50 pounder with a keel is at least as maneuverable as the 16’ Royalex Mohawk without a keel that I paddled for decades. I find that our 16’ Old town Ideal with a keel is a tiny bit less maneuverable than the 15’ canoe – but that is in part because it’s a bit longer and has a rounder bottom. I know that when we leave paint on the occasional invisible underwater rock, I am happy that it is paint from the ash keel rather than paint and filler from the canvas cover (though we may never have hit the rock if there were no keel). When the wind comes up, I welcome the directional stability the keel can give, because I am usually the stern paddler trying to keep the canoe on course.
And as to personal taste, of course, each to his own. Some people just like keels, and others just don’t. Ain’t no accounting for taste.
Here are some links to discussions of keels, their benefits and debits, and some matters concerning their installation or removal. The list was appeared a while ago in the Wooden Boat Magazine forums, and I have added a few.
http://forums.wcha.org/showthread.ph...highlight=keel
http://forums.wcha.org/showthread.ph...highlight=keel
http://forums.wcha.org/showthread.php?409-to-Keel-or-not-to-Keel
http://forums.wcha.org/showthread.php?12167-Old-Town-Guide-16-restoration&highlight=keel
http://forums.wcha.org/showthread.php?3292-Washer-Grommet-for-keel-screws&highlight=keel
http://forums.wcha.org/showthread.ph...highlight=keel
http://forums.wcha.org/showthread.ph...highlight=keel
http://forums.wcha.org/showthread.ph...highlight=keel
http://forums.wcha.org/showthread.ph...highlight=keel
http://forums.wcha.org/showthread.php?12629-Bedding-compound-and-decal-questions&highlight=keel
http://forums.wcha.org/showthread.p...-installation-dimensions-shape&highlight=keel