Hi,
The manufacture was Pulse Engineering, which is now called Pulse Electronics. Unfortunately, the part number 478453 is a custom part made for Fluke.
The only way to get one of these transformers is to find another Fluke 8010A.
The battery ones often appear to be dead, because the NiCad batteries fail short circuit.
Good Luck !!
Ciao
Jay_Diddy_B