Only being born a handful of years before the Nylon 66's were discontinued, I'm probably later generation than most people which are such staunch fans of the 66's. I had opportunities to shoot them from time to time, and I eventually bought one used at a farm auction when I was in high school, but I will admit - I recall hunting rabbits with multiple friends during high school and the reaper came calling for their Nylon stocks while we were afield, and I remember my Marlin 60 with real wooden stock feeling pretty good in my hands after that as they whimpered home with their rifles in pieces. I also remember a bunch of them coming to my door when I was working for different gunsmiths and shops, and when I had my own shop open - and I recall the same disappointment over and over as folks realized we simply couldn't get replacement stocks, realized the repairs we could do weren't terribly permanent, and realized the cost of repair or take-off replacement parts was pretty heavy compared to simply buying a Marlin 60 or Ruger 10/22.
They're neat rifles, and I do kinda wish my son (born 24yrs after the 66's were discontinued) would have a legitimate chance to experience one, but I'm sure not spending the cost to buy another one, with the stocks effectively being a ticking timebomb. Same disappointing problem with the XP-100 pistols, but at least the XP100's are a bit easier to resurrect.