Is that an extra lid lock on the front side of the lid? I have seen those commercial machines at some camping sites in Europe, but never with that part.
Because the agitator does not look like the Power Fin 12, I think this is a pre-orbital transmission machine. Maytag made these machines for OPL applications in extra large capacity; the agitator should have 16 holes in it (4 vertical rows of 4). I'd say a pre-1990 machine.
judging from the limited photo, yes, that is the classic Maytag design. slow stroke with straight-vane agitator. i had no idea these were sold in the UK. basic design dates from the 1960s.
in my limited experience (im sure a washer guru will correct me) the classic Maytag transmission was one of the more reliable components of the design. you might stock up on belts and the water fill assembly may be worn.
you asked about moving it on its back, good question. if you did that you CERTAINLY would need to lock the tub into place. where are the washer/Maytag gurus?
Well BIG disappointment, the "Scrap Man" got it before I could get there!!!
One consolation is that the extra pics showed it well beaten up, and now I know what the mechansim is I have seen quite a few of these around....here`s hunting