There is a 531 sticker so I'm pretty sure its a 630... the fork does not say anything about the steel its made of. I'm guessing the simplex stuff is original, cranks, maybe pedals, stem, seat post, saddle, bars... not original wheels, brakes, and levers. Did have my calipers at my storage unit so I couldn't measure the seat post.
its too bad the paint is so rough... I've got some other 531 frame ahead in the bike building que... so I'll have to think long and hard about either refurbishing this bike or parting it out and passing it on to another.