The TMB272 is quite a common set in the UK, the first portable TV capable of car battery operation.
Your set looks to have an excellent picture, the CRT's always seem to survive well, my set has a very good CRT, although it is patiently awaiting restoration.
The TX275 was obviously an export model, interesting that there is a multi standard version, I know that they were used as monitors by the BBC, but probably a modified 405 line only model.
Mark