If Dieter Hermann's book on the 190D9 is to be believed, there is no evidence D-12s ever made it to a combat unit, with evidence of only 2 D-13s being delivered. Production delays kept them from ever getting into the war.
But I tell ya what. If you can convince Hitech and company to give us the Spit 21, or even the Spit XII, both of which did see combat, you can have the D-12
The surviving bird mentioned is one of those 2 D-13s