It is a friend's model and he brought it to me as it did not work. Mainly a servicing job, refitting a coupling rod to the crankpin and sorting out the wiring. He has lots of British OO scale models and brings them to me a few at a time for repairs/improvements/servicing, etc. This means I get to see and handle quite a range of models on the layout. Good thing I made the wiring of the layout switchable between DCC and DC!
Garratts were used by the LMS here in the UK and just this one by the LNER. But they were very prevalent in South Africa and several other southern African countries, on 3'6" gauge and were highly successful on bendy mountainous lines. Basically two locomotive chassis with one big boiler. Scotland did a great export trade in Garratts!