My experience is with slightly newer 50's but my understanding is that the early 50's shoot similarly but display better quality with more cast parts as opposed to stampings.
I have always found the 50's shoot very nicely with mild, maneageable recoil and excellent accuracy. Neither of mine are hold sensitive and i use them for informal target shooting at 10m, mostly. They seem to like a wide range of pellets but various RWS wadcutters especially .
Like any tap loader, tap seal can can be probablematic with wear but the 50 isnt especially prone to it. If the tap still has its usual, positive action and doesnt worry a small piece of tissue of some powder placed over it during a test fire it should be fine.