So, cleaning the jacks a bit more seems to have had a positive effect. I'm getting a good signal and no crackling. I still have some doubts, anyway,...
Indeed, if you are patient and keep looking, you might even be able to find a Gibson plain A. That is, one without the headstock logo. I've succeeded...
After reading through all this a few times I got to thinking, and one thing I thought is maybe I didn't dig deep enough on cleaning the jacks. Spray...
If I may quote Barat, "Wa wa wee wa!" :disbelief: I feel compelled to do so because I do believe "spuir" is name in glorious language of magnificent...