if you can find the braided nylon, its pretty easy to do. the secret here is to soak the nylon overnight in water. when you start the wrapping, you have to apply considerable tension to the nylon to get it to stretch. you can invent some convenient means of doing the tension thing i am sure. the wet nylon will stretch alot so when it dries, it will be even tighter. beginning and ending are the same concept as wrapping rods. if you have never done that, you can find lots of detailed article with a google search.
Yep, do it yourself.
I've wrapped oars for my pontoon boat. You should be able to find matching rope in places like SportCo in Fife or in Homedepot, Lowes, etc.
You will need to do the same type of under wrap as is done when wrapping guides in rod building. (do a search for this) Also, most oar wraps are taped off with black tape. Just cover the tape in a thin coat of rod building epoxy.
You will be surprised on how much rope you use, so buy more than you think you will need. Measure to ge a "ball park" figure.