Is TR8 front cover same as SD1?

[turbodave]

I always assumed it was the same; the PN in the catalogue suggests it is the same, the TR8/SD1 pump gears have the same PN, but strangely the pump cover has a different PN for TR8 vs SD1
This has flared up in a FB group, and I'm confused why one individual is very strongly insisting it's a different cover for each (in spite of the factory part catalogue PNs) ; and references Ted Schumacher and others as validating them being different.  Anyone have any real insight?