I just picked up a rough number 1, 2nd issue and was wondering if there are diagrams of these early models available? Specifically the barrel locking mechanism.

Yes, there are several books describing the gun and it's mechanisms. See page 171 in David Chicoine's "Antique Firearms Assembly/Disassembly" for example. The NRA's series on exploded gun drawings also show the S&W Model 1. Ed.

Nuguy, welcome to the forum. I believe there is an exploded diagram of a model 1 on David Chicoine's web site. I think his site is oldwestgunsmith.com. He is also a good source for parts. Hope this helps.