I'm trying to work out what my dads old air rifle is. The only info I have is that it is at least 50 years old - probably more as I doubt it would have been bought new, believed to be German. Caliber is a bit questionable - I tried a modern .22 pellet and it is too tight to fire so I'm guessing it may be a .20? a .177 is too small.
It looks a bit odd in this photo not sure why it looks like the barrel isn't lined up correctly....
Only markings I can find are the 4 digit serial number and a circled B.
Can anybody shed any light on what it is and where I can get spares from please.
Thanks very much
Edit close up photos: