OK, I know I should be able to figure this out on my own, but can anyone give me the lowdown on how an SVT screws into the head box? Here is my situation: I have a mid-70s SVT that is in good working shape but has a really thrashed head box -- like the wood is disintegrating in places. I bought a new head box from Fliptops, but it is not obvious from looking at the amp exactly how the head screws into the head box. I know the power amp section and the preamp section of SVTs are in two separate pieces, and I can see that the power amp section appears to just screw in from the bottom of the head case. But I can't tell from the outside how the preamp section attaches and I don't want to start taking it apart until I understand better how to put it back together. Any help? Thanks!