You might discover, however, that when you rub an oily rag over the cylinder, to preserve the metal from rust, eventually this will discolour the sticker and/or cause it to fade.

I recently acquired an FWB 127 and I recall reading, somewhere on this forum, that the washer/seal at the end of the piston, has a habit of disintegration after many years. You might like to bear that in mind, given your rifle is probably around 35 years old. In addition, given it seems not to have been used, you will probably find that the power increases after it beds in.

Out of curiosity, where did you manage to find a mint and unused specimen after such a long period? Who owned it but did not use it?