Just bought one and I am a little worried as the serial number is 6 which it would seem has some history but I have just spent £140 on fixing the trigger mechanism as the rear screw had duff threads and the barrel was misaligned so it was leaking air everywhere. But managed to sort all the problems out took me about 4 hours and its fine now. As for additional info I am led to believe that the gun has interchangeable barrels if you can find the .177 and .25 versions. The power can be turned up by twisting the barrel but I wouldn't recommend it as you are asking for some serious trouble. Parts are hard to come by and you will have to find a really good gunsmith. But all in all i am very satisfied with mine now it has been fixed and it is a good addition t my collection. I will be restoring the stock as is has a few dents and scars but nothing too bad it can't be repaired with some TLC. Hope this helps