Identifying an old tuba with a unique engraving

[smford1241]

This is a tuba that an acquaintance has, it is used as decor, but is operational from what I've been told. The engraving is obviously done by hand but looks familiar. The tuba itself reminds me of a lot of older European no name brands. I personally play a Cerveny Kaiser 601 from the 50's. I was wondering is anyone is familiar with this tuba or the symbol that is engraved?

[daktx2]

This screams Russian / Leningrad, but these are generally hard to trace exact years and have had all kinds of brand names over time. I haven't seen that particular engraving before. The ones of these that are actually put together well tend to play well, but most are pretty haphazardly assembled.