It's hard to put a value on a canoe without seeing it in person. No matter how good a canoe may appear in pictures, those who have restored them know the sort of "surprises" that can be lurking in the hull of an old boat. It's always up to what the buyer is willing to pay, in any case.
If a buyer plans to hire someone else to do a complete restoration, the cost would probably be around $3000, and "in today's economy" (don't we all LOVE hearing that when we hope to sell something) few canoes reach the $3K price... so a buyer such as this would need to be someone who wanted a Morris and saw the advantages in yours. But that buyer might only want to pay a few hundred dollars, because they would need to put so much more into it (money-wise).
Your canoe might be more valuable to those who want a Morris (they tend to be a desired species of canoe) and are able to work on it themselves. If you look at the link Greg provided on "canoe value", you see that a water-worthy canoe is worth about $1000 (give or take). If your canoe can be paddled as-is, thus allowing use of the canoe right-away, with restoration happening when time permits, you may get about a thousand for a Morris that has remained in the same family and hasn't been hacked-into by someone who simply wants to get it back into the water. Someone looking for a winter project might pay nearly that much if they are looking for a Morris that hasn't been worked-on before and doesn't need much done to it... some folks don't want to strip the inner varnish, etc. It really depends on what the buyer is looking for.
One more thing to mention is that "these days" it seems folks are looking for canoes 16 feet in length or less. The most common Morris length appears to be the 17-footer, and there were a lot of 18-footers made as well. In the early twentieth century, these longer boats were desirable for a couple reasons: those who used the Morris for fishing/hunting needed a big canoe for all their gear, and those who used the Morris for courting needed a big canoe for all the courting-paraphernalia (blankets, pillows, picnic supplies, Victrola, etc.) but these days, folks want something that can easily be placed on top of a car. That being said, anyone looking for a Morris might be inclined toward yours in spite of the extra couple of feet, if it fills the bill in other aspects.
Wish I could persuade you to enjoy the canoe yourself-- it's a wonderful thing to have a canoe that has been in the family for over a hundred years! But it's also wonderful to re-home something your family has had stewardship of for such a long time, and to know it will be enjoyed by others.
Kathy