I just found the ad, too. I think it's a 712, because it's got Reynolds 531 tubing. That gives it even more cachet. I have a 500 series with Ishiwata 022, which is comparable to 531 but a bit stiffer. 022 is good for me in a larger size, but Ishiwata 022 doesn't quite have the same cachet.

The frame is what's most noteworthy on the bike. The components are serviceable, but nothing particularly special unless something has been upgraded.