I've got one. I saw it in the far corner of a photo in a magazine recently. I'm 90% certain of what it is, based on where I found it, but I'm interested to see what you guys think.
This is a Yak-4 initially marked as Yak-2. However, the small air intake at the side engine nacelle and the shape of the exhaust pipe indicate the M-103 engine. So it should be the Yak-2 rather bacuse Yak-4 was powered by the M-105 engines. The M-105 nacelles had the air intakes removed from sides and moved to the bottom and front of them.