[Doug Stankey]

Actually, the "L" prefix indicates that it is a Luftwaffe FPN. The Luftwaffe contained many odd specializations including Pionier units (with black waffenfarb). There was a lot more than just Fliegertruppe, which is what gets most of the attention in most published matter.
For example, we have notes on several officers who held the post of "Ortskommandantur".

I hope that this has helped in some way.

DGS