What type amp do I have

Although my beginnings in this hobby go back to the mid to late fifties when tubes were what we had, I'm relatively new to tube amplifiers.  I recently purchased an integrated amp of unknown manufacture. It has no schematic and the only identifying indicator in English (everything else is in Russian) is on a strip on the back of the chassis which reads " Moonrower made in Russia Moscow" and a handwritten serial number (?). The currently installed output tubes are 4-Mullard 6L6GC.; the inputs are 2-6J3P and 2- 6H23-N.  It has two volume controls (R&L). I've given up trying to identify it so now all I'd really like to know at this point is what type of amp it is.  My main system's amp can be used in either triode or ultra linear mode so at least I know what its mode of operation is.  I don't know what I'd do with this knowledge but it would be nice when asks, if for no other reason, to be able to tell them. All I know for sure is that it's a great sounding amplifier.  Any comments would be welcome.