The Showmasters are not thru-neck guitars rather, they are set-neck guitars along the line of Gibsons. When they were current on the catalogs, they were advertised as having Mahogany necks and a Basswood body, but I can see through the finish on the back of my S-S-S guitar, that the body as actually African Mahogany as well as the neck.
When I got my first one in '07, it was hanging on the used guitar section in GC, and I picked it up for $250. It had a very comfortable neck and was in good shape, so I bought it. It came with it's stock pups which were SD's, (Pearly Gates in the bridge, and RWRP JB in the neck). As soon as I plugged it in when I got home, I knew those pups were out of there. It was all high end, and thin sounding. Currently, that guitar has the Air Zone in the bridge, and the Air Norton in the neck. The Air Norton actually delivers more of the kind of sound I want to hear from the guitar which is a full range type of sound with a lot of clarity all around, and it does have a decent emphasis on the low end. The Air Norton seems to have a lot more output compared to the Air Zone in the bridge, and I've toyed with the idea of replacing the bridge pickup with a Norton to balance the output a bit more, but I don't want to lose that warmth. The Airbuckers are advertised as a warmer. more vintage version of their original counterparts. For a short time, I did have a Tone Zone in the bridge of the other H-H guitar, but I took it out because it was too nasally for my taste, too much emphasis in the upper midrange. I replaced that with a Steve's Special in the bridge, and that guitar now produces tones that are very reminiscent of Waddy Wachtel's tone on Warren Zevon's Werewolves Of London.
I have been thinking that I may try a Mo Joe pup in the bridge, but I'm not sure if I want that kind of tone in my bridge pick up, as that could be a little too muddy. I may just get a Norton and try it.