[Arran]

I think that Terry may be right, the power transformer is a replacement of some kind, though the mounting is the same as the original, I wonder if it came out of a larger radio or a TV set? One way to identify what winding is which is by measuring DC resistance, it won't tell you what the voltage ratings are but it should tell you which is the primary, the H.V secondary, and the two filament windings. Then after you sort that out you can try powering it up and measuring for volatges, but be careful with the H.V secondary, there is 700+ volts AC there between the two legs.
Finding an exact replacement transformer would be near impossible without getting a parts chassis, there aren't too many that have three filament windings, one of which is center tapped. Center tapped filament windings went out with directly heated tubes like #45s and #71As, with indirectly heated tubes like AC loctals it's not really necessary.
Regards
Arran