This is great info, thank you very much everyone. Looks like I have some homework to do! I'll see what measurements and date codes I can find based on the suggestions above and repost tomorrow (waiting on amazon to deliver some calipers so good timing).

The other thing I was toying with was a re-paint/powdercoat. Seeing that it might be hard to determine what it originally looked like, and also most likely a frankenbike, I'm second guessing that idea. Any suggestions/experience doing that with older bikes in that regard are appreciated as well (not so much the process as I've found a number of posts on that, more so if the frame's age would not make it advisable).

Thanks again everyone for your help and feedback!