They are NOS SNK LS-30's, which are the exact ones used in Heavy Barrel and Ikari Warriors. My last panel had a set of Happ Optical Rotaries but I had to practically cut a hole through the bottom of my panel so that they would fit, height-wise. These are short and work great. You just have to route deeply into your panel to mount them so that the joystick is high enough above the panel to move. I got the set off of E-bay after lurking for months for them.
They are connected using a GP-Wiz40 Max with rotary support. I tried a U-HID but had problems with a single switch rotating the wrong way. I also tried a Ultimarc Rotary interface but it would skip pulses if turned too fast. The GP-Wiz works flawlessly.