YAK-1 fighter under test-Rechlin?

[kaki3152]

Here are three photos of a captured early YAK-1 being tested by the Luftwaffe. I asume it's at Rechlin A/F but do not know. The registration, EL+LI, on the side of the YAK-1 is noteworthy.
Also, can anyone identify any of the high ranking officers? Any information is welcome.

[researcher111]

Photos are not very clear and therefore hard to identify ranks, I do not think that the YAK-1's depicted are from Reichlin Test Center ,rather occupied Ukraine or Belarus .

[kaki3152]

I know, I had to blow up the photographs which were not very clear in the first place. Figured it was worth a shot.

From photographic evidence, the Luftwaffe captured a number of YAK-1s, some with the cut down rear canopy. Still, this is the only photographs I have seen of this example.