What a neat find. Congratulations.
I'm sure even today in Southern Germany one occasionally finds evening air rifle shoots in rural Gasthauses. Back when I was there in the 1970's-80's it was all offhand at 10 meters, often using older, house-owned, Schutzen-style heavy .177 pneumatic rifles.
If you were the coach of a service rifle team with a few hotshots with swelled heads, these were a great curative, as an air rifle @570fps and reversed recoil requires a degree of follow-through unnecessary in a high-powered rifle @2700-3200fps. There's nothing like getting your eye wiped (and wallet emptied) by a lineup of ancient (and tipsy) local farmers to encourage a bit more dry-fire practice breaking those offhand shots.