@Ilwrath
I think you're looking at the four pin audio connector.

@Redrumloa
I'm still working on the Catweasel installer. Jens has been incommunicado the last couple of weeks, but I think he might be out and about.
I've also (hopefully) spurred Jens, Toni Wilen, and multidisk.device author into working on the problems with WinUAE and the latest multidisk.device--something to do with the device ignoring the prefs file.
Quick notes from my own experience. On the Catweasel MK3, I had to remove the uppper joystick port and mount it in a separate slot. It's too high on the backplate to be usable in my Antec cases. On the Catweasel ISA, I had to remove the backplate completely--the ISA fingerboard is properly spaced and notched, but the standoffs on the backplate are a bit too long. :-(
I don't have a copy of Amithlon, but one of the projects I'd like to see someone try is running isacatweasel.device and multidisk.device on the same system. Per Jens, it should be possible, but it hasn't been tested. You can use isacatweasel.device on WinUAE, but the emulation itself only recognizes a single device (through the catweasel_io config option).
Trev