I have purchased a Old Time 1940's canoe and need to know how to clean it up and make it look good. The structure of the canoe is excellent it is improving the finishes that I am concerned about.
If your exterior paint is sound, all you may need is a new coat or two of paint. If it is cracked and chipped, it may be redeemable, or it may be beyond reasonable hope, and a new canvas with new filler and paint may be the best option..
If the interior varnish is in good shape, a light sanding and a coat or two of varnish may be all that is needed for a nice looking interior. But if it is worn or cracked and chipped, it may be at the point where stripping is required to get a good-looking interior finish. And if you are going to strip the interior, it may well be best to remove the old canvas and do a complete cosmetic restoration.
There is a wide continuum between needing just a bit of touch up and needing to strip the varnish and replace the canvas, and we can't even guess where your canoe falls on that continuum without good close-up pictures.
However, you might want to take a look at these links for how I have dealt with my canoe for the past few years -- I expect to strip and re-canvas it this winter: