Make?

[Nick]

Any ideas on the make of this small 4 valve AC/DC set?  Clue,  541U on paper label.

Looks like someone has taken the radio out of an early Marconi radiogram and put it in another case? 
Scale looks like a 541 radiogram from 1935...

Edit: Looking closely, it only has speaker cloth on one side, so I think it's a retrofit in an older case of an I-don't-know-what!