Oh man thanks guys!
Aye, I clearly meant 531 not 551 and that was an assumption based upon a decal I had remembered seeing (I thought on this bike.) I've never given this bike too much attention my Ex-girlie used to ride it, but she finally got tired of not being able to reach the ground and bought her own. So now it's back to me and I like the thing so much I'm turning it into a project build. I'm in Toronto at the moment and the bike is in Orlando, so I couldn't get any pics or take the measurement myself. I had assumed it was 531, but I'm certain it's made in Japan as I've read the "Made in japan for PUCH" sticker far too many times. So I'm guessing this is some other material??? Cro-mo??? what??
Honestly though this is going to help loads for my ebaying of parts so the bike will fit me again.
New Post, wheels, cranks (I have the old ones around), etc. You are each a wealth of knowledge and great. ;>