This is the reply I got about the tubing:
Item: retro dave yates diablo (250043670659)
This message was sent while the listing was active.
skinnyassazzurri is the seller.
i think it s a 61 c to c top tube,i can t check as i m selling it on behalf of a friend..and the tubing we think is 753, i know a few of the builder s aswell as dave yates and they all seem to think it s 753
cheers
dave