Bob - hmmmmm...building one myself? I thinking of down-sizing the home and doubt if I'll ever again have the room or workspace to do it...
Dan - I took all the suggestions on canvas and did some research on the number of threads by weave and warp, yarns per thread, yarn size and all that and figured the covering was just a base for the filler, i.e. the voids between the threads were more important because that's what anchors the filler than the type of thread, etc. When I looked at cost, this cotton/hemp blend was a couple of bucks a yard compared to the cotton-only canvas...no-brainer from a cost viewpoint and like I've said before I wanted to try this out as an experiment to see if I could actually do it!
Mike - The same brother who had this one sitting around for 10 years asked if I wanted to take a crack at his 18-foot freighter! That might be an interesting job, eh?
dboles - #1 project completed - all digits still attached - #2 yeah, I know, but sometimes they just jump out at ya, don't they?
Thanks for the kind comments, all!