have you considered buying a small set off a 60s honda? sometimes Craigslist has the least expected stuff. You might get lucky.I have always wanted to build one. The problem I have come across is the cool looking fiberglass or composite "bags". I do have a lot of the rest of the bike built.
Yea, the plaster should work in that ideal, not to mention it sets really fast, even for a harder shell to work with. so that might also alleviate your time some. I think a fitting of my hand took 12 hours, so maybe a day and a half sitting [giving you time for something else]..and you should be in the clear there. I hadnt accounted for the amount of time it would take to evenly contour.. but Im sure theres a simple method in relation.I have a few ideas in the works. Another issue is time. Been extremely busy lately and will be for about 6 more months. If you look at photos of baggers the contour of the rear bags follow the fender perfect, so there is a ton of custom work involved. That's where your plaster idea is on point. I was thinking ammo cans, a welder, and bondo. As of now I have a 29x2.2 up front and a 24x3 in the rear on a spaceliner frame that I stretched the stays for a 3" tire. All parts are black. On the chrome frame it looks good.
Those are perfect! They are the same size as bicycle panniers. Nice Find.