[TenTec] Slightly OT: Astron question

[Michael Tortorella]

G'day, all: I know some folks use Astron supplies with TenTec rigs. I have
just ruined the SCR in my Astron RS-20A (stupid - don't ask) and am scouting
around for a replacement.  The SCR is a S0535W which is a 400V, 55A unit.
My ? is could it be replaced by a higher voltage and/or current SCR (e. g.,
600V at 70A, etc.)?  Any insights appreciated!
Thanks and 73
Mike W2IY