I recently bought a 630 frameset from another member. I was originally going to build it up as a fixed gear, but I may restore it to original as I have most of the parts.

I agree with some of what T-Mar has written. My 630 does not have shifter braze ons and did come with a steel post. As he said, though, the 630s I've seen do not have brazed on cable stops. I think you have a 620. I agree that this would be a great platform for an IGH build.

I would clean and polish it and build it up from there.