In excellent, all-original state, that bass would have been worth somewhere in the region of a grand, maybe £1500 if the vendor got seriously lucky, but also maybe £750 on a slow day.
For something as beat-up as that, and needing quite a lot of work, £255 was probably a pretty fair price.
In my vintage-Hofner-collecting days I had a large cardboard box filled with genuine, original parts for old Hofners that I'd accumulated. If I was still in that position, I would happily have paid £255 for this bass, knowing that I could pretty much restore it from my own parts bin.