Wes rebuilt mine around '91, after I purchased a '74 Spider that had been driven infrequently. Gas began leaking into the sump. Since the rebuild, no issues. Wes executes a number of upgrades during the rebuild process that eliminate the most troublesome weak points in the pump's design. He has definitely performed more rebuilds on these pumps than anyone on the planet.
My only complaint was the thermostatic actuator he provided, which was rebuilt by someone local to him, and gave me trouble. It wasn't w/i spec. and had to be replaced soon after with one from a guy in SoCal, that Jon/Alfa Parts recommended. It has stainless steel piping, and has lasted a long time.
I like the fact that the Spica, once rebuilt and calibrated, runs like a modern car, w/ minimal attention - must be that diesel lineage

. So, unless you intend to constantly bounce the tach needle off the redline (max. is 5600 rpm with these), I think you'll be pretty happy with the results.
Considering the relative scarcity of mechanically injected cars from the 60's/70's, the Spica system represents a unique, successful and graceful approach to addressing the emissions concerns during a very stressful period in the progression of automotive development.