Re: L frame cylinder....
I like the looks of the unfluted cyllinders also. If the other sources dont work for you form some reason you might try SSK Industries in Wintersville, Ohio. J.D Jones started the business I believe and he of course is famous for lots of wildcat cartridges for Contender pistols.
I have been to the other world of custom guns and I can only say
it can be an expensive trip. You may have to get it out of your system. Be sure and use a reputable outfit to do the work that will stand behind there product. Basement wannabees will take your money and do nothing for you if it doesnt turn out. Just remember small claims court can help you out.
I may be incorrect but 15 years ago RSR wholesale had a run of Model 66s with 3 inch barrels and maybe unfluted cylinders. You might try Gun Parts Corp and see if they can help you on this. It would give you a two-tone revolver. Double check with them as I may be incorrect so dont get your hopes up too much. Good Luck.