AVL Roadrunners are controllers for multiple slide projector shows. I have only seen standalone ones like the commodore type you mentioned. Since this one had video it is probably for adding or switching video in a multimedia show. That thing is probably Z80 or 8 bit controlled, maybe STD bus. All of the pieces go together. This must have been a high end system, probably worth saving. IIRC AVL stands for Audio Video Laboratories.