I've been trying to find one for ages in good nick - we had them at BBC radio and were the simplified ones - some didn't even have a record button! They had a really good digital counter instead of the mechanical one. I think they were all ASCs. Lovely machines and really tough and reliable. You can get a working B77 for around 500 pounds, but you never see PR99's - even the stripped down ones for less than a grand in working order.