Thank you for your responses!
Very portable to get he right background (not all of us have meadows, fields and distant woods right out of our back doors!).
Yes, it is not easy to find a location around Munich, and I was there by car.
Where I thought from memory it could go, there was maize as tall as a man, and in many other places there are structures that don't quite want to fit a WWI biplane.
One thing that looks a little off, though is the shine on the grass. Could it be toned down with a spray of dull clear?
Yes you are right! Got the same tip in a German forum

Will do, but too late for yesterday's session. At the moment there is a lot of rain.
Cheers,
Frank