I have a Classic Bridgestone RB-T size 53cm for sale that is in excellent condition. The frame dimensions are as follows: (Seat tube center-to-center 512mm, Top tube center-to-center 545mm)
This bike is a beauty. It has the original tires on it. The only thing not original is the saddle.
Here is a link to my CL ad Bridgestone RB-T Classic touring bike
If you want to read some cool information about this bike, it can be found on the Sheldon Brown website
Bridgestone Bicycle Catalogue 1991-32