Re:
I feel your pain, ed.
Deciding what bike gets culled is harder than deciding which toe to cut off first.
You will find a reason to keep them all.
End of the day though, ride whatever gets you out and be honest with yourself. Retro bikes can be punishment to ride and, take a month to recover from the episode. I know that.
Keep your clockwork and have a comfy modern bike so you have the best of both worlds for whatever terrain you are tackling. Most guys in our region ride modern now.
My solution is to ride less, running and swimming has taken over and requires less kit and planning. Shorts, towel, trolley coin for the locker and i'm sorted.
As I don't generally do suspension and effective brakes, I choose routes to suit my bike rather than the other way round. Which, can be a roother
cause of having 10 bikes. 'Bike for each purpose' phenomenon (don't get me started about single speed). Marc says "buy a bmx, then"
Good luck in your course of action,
Remember.
Keep off eBay.
Hide old retro bike related pics.
Avoid readers bikes >1997.