Sorry I didn't catch up sooner. The relay bases were the way to go for sure, especially if you are using 2 or more of the same relays. Trouble shooting any suspect relay just becomes a quick swap to see if the problem moved with the relay. Even on bases with hidden (bottom side) terminals, testing wires, or testing with them, you just pull a relay to expose the female terminals, and use a meter's probes there. The use of a relay socket is one of those things that seems like overkill till it comes in handy, then your very glad you did it 
On thin plexi, try a dull bit and/or even run the bit in reverse, to heat and soften the area with friction, then forward to cut. Thicker stuff, alternate and heat well just before cutting to finish the hole. I first learned to heat plastic playing with an old building toy set. It used a plastic drill-driver to spin and friction melt plastic rivets into place. I was trying to remove them with my geared hand drill but kept cracking the thin plastic sheets once the rivet head was off. Gramps saw this and then taught me to sand an old bits tip dull to stop grabbing on the cold plastic, and cut on the soft, and/or melt 100% through it spinning in reverse.
A great toy for me 
, but they stopped producing it long ago. I'm sure it was because of some less careful kids burning their fingers more than just a bit, or they were breathing the melted plastic's fumes till they were ill 
. Lots of fun though.
Nice chair! And I'm sure "Auntie Ray" would've appreciated your appreciation.
I didn't even make the connection till I stumbled on a photo of her doing research on the chairs. I remember hearing "Herman Miller" and Eames a lot growing up, but didn't really know why till I saw her photo. She was either a very close friend of my Grandmother, or a distant relative, but my aunts called her "Auntie Ray" and she doted on me a bit when visiting. I don't remember ever meeting, or hearing about Charles though.
We've got some possible one-off, padded fiberglass seats, with bright orange, heavy vinyl upholstery & tan trim, in the stacking DF series (? DF ?- H.M. logo embossed & tagged, but faded, or not fully marked on the tags, and I never found the exact chair/leg/upholstery color combo to know the series for sure. I also had a tan set on a swiveling, rolling, pedestal base, similar to yours, but 4 aluminum legs with a tapering 2"-3" flat, vertical, profile . Made in the same tan, a chemical spill of some kind melted the vinyl on three before I moved in.
I'm looking at the forth tan DF right now, sitting in front of a mini-light table (drawing/drafting) that's fast become my work desk, and testing track since I mounted an 0-19" oval on it.
Though still very comfortable, I'm awful jealous of yours 
.My uncle has a similar lounger but "puffier" and in a deeper "woody brown"/ "woody brown", and the stool too. But the stool has 3 taller side panels, and is a squared off, puffier cushion, on one end, and then an arc tapers down like yous on the other (it was once here too).
