I did a Google search and found some pics of a Deutschwerke rifle.
While there are some superficial similarities, none of the rifles pictured had the articulated handle in front of the stock. It seems that the Deutschwerke has a pivoting breech that flips forward to load/eject, and there is a spring driven striker that (I assume) is pulled back to cock.
It's possible that you have another one of DW's products; It certainly is an oddball. If I understand your description, the rifle actually fires when you release the forward actuator handle???
The DW trademark, which does resemble an "A" is actually a reposing lion shaped to look like the letter "D".