It look's like an 80 watt charging set. I've been looking out for one in the UK for a while. They come up on EBAY occasionally(the last one was about £35-but was collect only). And a chap had one at Beltring that he wanted £200+ for

(he claimed to have had an offer of that, but the bloke didn't have the cash on him). I presume they were origionally 12 Volts, but some might have been converted to 24. As a radio repair trailer I have would have been fitted with one, and it used 24V.
And can somebody now tell us What it's really please