[Identifying an obsolete Varo rectifier?]

Thanks for your reply.  I have two pictures I have attached.  I plan to sketch a circuit diagram this week which I will post.
The Aluminum heatsink is not taken to earth but a wire from the block it bolts onto goes to two other points in the system.
regards. Jack

[Identifying an obsolete Varo rectifier?]

Varo R153 Rectifier? (7803 - wk 3 1978?)

Hi There, I wonder if anyone could please help me identify the above component (and a possible source)?  It is part of a Woods Ultracon U-100
Motor scr cotroller and is the first component across line and neutral (240VAC) after the switch.

The device is press fitted into a heatsink and has 3 blade terminals on an insulated post. Line and neutral are across two (with a dead short between them - hence the reason it is tripping the 16amp CB.)  The third terminal  goes to F2 (Motor field coil) and another point in the unit.
Using a multimeter, there is a diode drop from the third terminal to line and also to neutral.

A datasheet  would be perfect but any information would be appreciated.
best regards  JAck