Welcome to the forum RJBAudio yeah this is a great resource for repairing amps etc !
You may find this handy
Peavey factory semiconductor cross reference
I'm the newbie! And I got questions, many questions!
(the above is the URL !)
posted by Enzo.
I think that you will find the 70483100/70473100 are in fact MJ15015/MJ15016.
Its highly likely the driver transistors have been stressed and need checking too.
Also check the nearby diodes.
The MJ15024/MJ15025 would be an upgrade in "ruggedness" but shouldn't
I gather Peavey U.S. are very helpful and should be able to supply you with schematics and spares.