I'm thinking of using a TA Triplizer and a wider BB to add a bailout low gear to the PSV. It has 53-42 and 12-24. On steeper climbs, I can keep up with modern riders and their compact doubles, but I'm working hard in 42 x 24 while they're in their 34 x 28.
I have some larger Heliocromatic freewheels which will get you to at least 28. I think your Campy Victory/Triomphe will swallow a 28T if you are still running the OEM on the PSV.