Well, brute force success

Managed to wedge off the top/front (mostly) with a screwdriver or two. What the problem was after 30+ years of use, there was a wee bit of gunk in the pathway where the safety switch is. There was enough in there that it prevented the arm from rotating when the bowl tab was inserted.

I was able to lift the top off enough to slide the lever out. It's just a longish plastic piece with a hole part way down. There is another squarish piece with a plastic tube that slots into the arm. When the safety tab slides in, it lifts that arm (pivots on the plastic tube) and rotates so that the end of the longish piece forces another part down that allows electrical contact to be made/motor engages.

Kinda neat but still can't figure out how the lid/side was held in place. The top had tabs that popped out of holders in the side but still can't figure out how the bottom of the front piece was held in place to the actual bottom.

In any case, runs like new now (a few gouges not withstanding) under no load. I can't see it getting much use now that I've got the new replacement.

Thanks to all for reading and offering some suggestions