Hi Iain, What does the serial plate on the back door say? Does it also specify the voltage? I suspect you have a variant of the American amplifier built in your country. I live in England and have seen imported Amis from Italy made by microtecnica, nova from Germany, Eden, International. This was common practice around the age of your machine due to import restrictions etc. We in the UK had bal Ami. There are all manner of genuine variations on that amp I've seen, with different tubes in I reckon maybe the local factory probably screen printed 6973 on by genuine error because they were copying the American one. Obviously the size of the valve base hole in the metal is bigger with yours, so it could not have been an enthusiast hacking around as the 6973 print would have disappeared when they enlarged the hole for the valve base. I've seen Rowe Ami JAL jukeboxes with continental mechanisms. And continentals with Ami I amplifiers. All legitimate. I think, ignore the print. You're in a better position with yours as the 6973 can be a bit of a fussy tube and there are lots of badly made repros of it about. Nigel, uk