Well, I took the advice of everyone in this thread and purchased my first S&W!
I did some research and found that the one I got is a 1981-production 15-4. I was a bit confused at first because it has an un-pinned barrel. Apparently some of the late 15-4's have unpinned barrels because they were starting to transition to the [un-pinned] 15-5. But regardless, I did my best to check out all the items mentioned in the "revolver checkout" sticky in order to narrow it down to my chosen Model 15. Definitely some cosmetic wear, but it locks up as tight as any I handled and the bore looks great. This one also has the original wood grips.
There is also some very slight surface rust, but nothing that will leave any pitting, and no damage whatsoever to the bore or crown.
Although I haven't fired it yet, I'm very happy with my purchase. Thanks all for the advice!