This is what the switches came from i am almost sure. The B&K 400 Cathode Ray tester. I saw one up close at the antique store the other day and it has the concave top and the button is wider than it's shaft. Hard to see in this pic. It has 2 of the black buttons and 1 red. There is also a Model 440 that has 1 black and 1 red button. Also I think the red light from this is what was used on the Farmsworth stand. the antique shop wanted $100 but i got 1 on the bay for $25 shipped. I'm going to change out the switches and sell it off as modified. Maybe i can get a little $ back. I will post good pics when i get it so you guys can make your own determination.