1 Opie 4 months ago I have a Peavey Delta Blues amp I decided to sell as I need to unload a couple amps. Lovely amp,just not using it as much as I should. I'm shooting a bit high ($475) as I don't need to sell, and today finally got a guy who is possibly interested in a trade for a Ampeg Reverberocket. Link From the pic's it looks to be in good shape,will know more this afternoon.I believe it to be more likely a '65 as I think they used 6V6 before then.It's my understanding that they went to 7591 for less distortion as Mr Hull was a jazz purist. The 6v6 amps are apparently more sought out hence more sellable. A vintage amp in good shape should ,in general, be easier to sell . That said I'll probably trade and toy with it awhile. Looking at the schematics it looks like it'd be easy to rewire for 6v6, but what I'd like to try IF it's doable would be to add a 5PDT switch somewhere not easily gotten to that would switch the wiring from 7591 to a 6v6 and back as desired. Preferably the switch would have a lock out feature to prevent any mis tripping of the switch. Does anyone know where such a switch may be found?