Dusty
Many of the Colt patent drawings are available. Someone here should chime in to tell you where to go (let's hope they don't take that too literally). I'd do a search.
I have never seen or heard mention of the Remington "plans". There isn't a lot to it and you would probably want to do an "armoury" conversion as the 46 Rim Fire factory ones aren't real practical. Five shot if 45 Colt, Six shot in 44 Colt and smaller.
I have a number of New Model Army and Navy conversions (original, Millington, Howell, and others) and can provide you with measurements. The Army conversion is pretty simple.
I believe Flint has done a number of these and might be able to help you with the parts if you want.
Good Luck on ya