My salad bowl sits on top of a silicone ring. I cut it from a silicone baking dish that had a flat bottom. It seems to work OK for now. I'm using silicone vacuum grease between ring and salad dish and the base.

The base is 6mm thick Al. plate. I just had it in the workshop so I used it.

For my high current feed throughs I tried two different options here. I'll go into them later.

There are also two signal feed throughs. 5 in total 3 in one and 2 the other.

And in the middle there is a 1" copper pipe to the vacuum pump.