That is the exact unit I purchased off Ebay. The rated output isn't printed on the power supply, but the fuse is 3A 250V.
Fuse is irrelevant in the end...
Do you have the power supply? And if so, how does this plug play into the hookup, is it on the power supply or the unit itself? If it's on the power supply is it the input or output of the power supply?
If you have the power supply can you measure the voltage? The fuse is a good indicator that the maximum current is 3 amps (assuming it's the correct fuse) but we have no idea on the voltage rating...
I personally would just swap it out for a current plug configuration but before I offer recommendations I would like more input...
And last but not least, it might be time to crack the housing open, some nice designer might have included the power ratings inside, heck you might get real lucky and find a schematic glued to the inside of the housing...