Zute,
Before you too carried away with this,
a couple questions,
1st - are you a pro builder selling canoes for money? If so, then yes, you need to figure out where and how you will put the numbers.
BUT, if you are a hobbiest........,
2ed - determine just how concerned the state you live in is about the Coast Guard numbers. If your state DNR (or equivalent) actively enforces the CG reg, you still need to figure out where and how you will put on the numbers.
But, if they (your state) doesn't enforce it, then you have a decision to make.
FWIW, here in MN, they don't currently enforce it, (the future is unknown) and only care that you register it, pay your money, and put on the ugly sticker. To register a boat/canoe, you just have to fill out the paper work, they will accept any S/N or even no S/N.
Dan