According to this, yours is a 1991:

Rivendell Bicycle Works - Bridgestone FAQ

Seems consistent with the catalogue:

Bridgestone Bicycle Catalogue 1991-30

Catalog states Ultegra derailleurs, ritchey stem and Sugino crank. Frankenstein parts mix that seems very consistent with bridgestone/Grant Petersen. I don't know these well enough to know which fork crown they had, but simple google search should answer that.

Regardless, I'd say it's under priced if it rides.

As far as upgrades or changes...first things first. See if it fits. If it fits, ride it and see what tweaks you want to make. I would not look at this as a collector museum piece...I'd view it as a practical bike to ride and enjoy. Their desirability comes less from collector value than from practical value. How crazy you want to get depends on you...I would not worry about catalog spec myself, I'd make whatever upgrades made the bike more usable for me within a desired budget.