I recently purchased a used Kay attenuator found on Craigs List for $15, the date code was 1966. Here's what it looked like when I got it: The rubber switch covers had lost their flexibility and some of the switches would not stay in the up position. I removed all of the switch nuts and carefully clipped off the rubber covers with a pair of wire cutters. Some of the switches were intermittent so I sprayed the inside of the box with de-oxit spray, worked all of the switches and let it dry for a couple of days to evaporate the solvents. I cleaned the outside of the box and switches using rubbing alcohol and tissues. Everything seems to be working nicely now. I'm pretty impressed with the quality of this device, the switches are custom and the interior is all silver plated. There are even cast metal separators in the center of each resistor pi network for increased isolation. One unusual thing I noticed was a number of small capacitors (?) across the grounded resistors, I've never seen that in a step attenuator. I'm guessing they are some kind of compensation devices for UHF. Ideas?