Hello, I've been offered these boards.
They are white (silver) rayon type material on green cloth backing.
They have holes from one star and some branch insignia.
What puzzles me is their construction: They have been made like the sew-in type. Then they have been added the two cloth straps to turn them into slip-in models. yet it has been done rather proffessionally and the cloth is coherent with the one used during manufacture for the backing. Furthermore they have little moth-nips. All this makes me believe they have not been attached recently.
The stiffener is made of cardboard and the white thread is somewhat tarnished at the edges, which may account for them being vintage.
They look like somewhat narrower that the standard WW2 boards, yet no so narrow as the legal-medical (might be engineers or intendence) or the Bulgarian examples.
What do you think? Soviet? NKVD / KGB? Era?