I'm wanting to get back into air gunning again. Can I ask for some advice please? I've got an old rifle that I'd like to try and sell to put towards a more modern one. It's called an Original 35 .22 Made in Germany and there is a very small 05 77 which I think might be the date of manufacture as I've had it since about mid 80's. Are these old guns worth anything or have they been superseded now by the new gas piston designs?