I have never met a sizing chart on the Interwebs I liked.
Try another 62 somewhere - If it feels OK then it's probably OK, stem and TT length not withstanding.
It is too bad there isn't a headset you could put some wheels on it and stand over it. If it is too big it isn't worth buying.
Why do they have a stripped frame rack?
Bianchis '87 Sport SX, '90 Proto (2), '91 Boarala 'cross, '93 Project 3, '88 Trofeo, '86 Volpe, '89 Axis, '79 Mixte SOLD, '99 Mega Pro XL Ti, '97 Ti Megatube, , '90 something Vento 603,
Others but still loved,; '80 RIGI, '80 Batavus Professional, '87 Cornelo, '86 Bertoni (sold), '09 Motobecane SS, '98 Hetchins M.O., '09 K2 Mainframe, '89 Trek 2000, '?? Jane Doe (still on the drawing board), '90ish Haro Escape
How did you measure it? CTT CTC
Measured from the center of the bottom bracket to the top of the seat tube. As I am not a member there I am not sure what the policy is on which frames get stripped and which ones are put back together. Might depend on how much work it will take to resurrect and this one didn't make the cut. I couldn't find in the parts bin the bits for the bottom bracket so it might have been the donor for another Bianchi, or other Italian frame project. Was a little concerned about that, but new Italian threaded bottom brackets are available so not too worried about that.
Rivendell would not be my first choice for bike sizing info. If you're on the "too big" end of their scheme, the frame is probably too big for you. Nice frame at any rate.