Does anyone know if there is a book that covers this subject?
The Merchant Marine was a critical part of the Soviet economy, and I'm attempting now to locate information on its uniforms and insignia, particularly rank insignia.
I imagine that the uniform changed very little in the post-1991 period.
Here is a complete uniform I own. It is for captain (as in master of the ship, not to be confused with the naval rank of captain x rank or army rank of captain).
This set was bought in Estonia and is for civil shipping, possibly post-Soviet. The buttons are all-Soviet but the sleeve ranks are not the usual. This might be a local difference or a post-Soviet distinct sleeve insignia of the shipping company.
On the left chest is a graduation badge from some Tallinn civil shipping navigation academy and on the collar is a enamel badge from the infamous "Estline" shipping company that actually operated the ferry "Estonia" which sank in 1994 in the Baltic sea.
I recall once upon a time in Tallinn, must have been 2004 or something, I was in an antique store when an elderly man dressed in full civil shipping uniform entered. He had all his awards on his tunic - and wanted to sell the set. His rank was Chief Officer (three stripes on the sleeve). I did not buy the uniform, but I recall I made a photo with my cell phone at the time - however it is since long out of use and I don't have the photo any more.