Great find for you Randy. It sounds identical to my one except mine doesn't have the stand or the addon Reverb. The cutout is there under the serial number plate though. Mine is a standard ST (with in-panel topboost). I've had it only a couple of years now, and it's in such original condition that it's a keeper for me.
The rear panels on the ST speaker cabs were identical to AC30's, (unless you have a closed back version). You'll be able to tell by the screw positions. The audio connector would have been on the lower panel, left hand end. I can give you the measurements if you ever want to reproduce them.
Need help with a VOX amp!!
Moderator: jingle_jangle