Nice custom made case!Lovely and she smells vintage5U4G, 3x 6C5 and a 6P5Speaker connector nice…All sockets etched with the valve the amp was design for for that slotFairly neat layout and wiring (all cloth covered) nice sheilding on sensitive wiring in the preampAll electrolytics have been replaced and some resistors..Does the jobMmm one 47K resistor here should be 100KAfter going through eliminating all the possible causes of crackling it turns out this “mod” capacitor added across the output transformer inputs was causing the problem! removing her and we are back to his and crackle being well under the general hum level! Always look for mods to find where problems may be coming!All Resitors more than 20% out in value have been replaced and a decoupling capacitor added to the microphone stage (as was originally there)All together and tested good. Little more gain niow in the microphone input that sounds great for guitar 😉 Gibson early 40s tube amp… simple and lovely is crackling a bit quietly…