ShortScale.org

For some strange reason the valves in my RP65 112 are different brands and slightly different shapes.

They are both marked as 6L6, one as 6L6 GC.

The bloke I bought it off thought it had the original valves from 1978 (He owned it since about 1980)
It sounds good too!

Anyway, should I get a new matched pair or just leave it?

If I do replace them, what brand?

You should be alright, you can use different brands of tubes if you want.

I was running some JAN PhillipsECG 6L6 tubes a while back and they were pretty sweet, but a little expensive. I've had good experience with JJ/Tesla tubes and I like to order from http://www.tubedepot.com, they ship pretty quick.