Eric, I think that Randall answered your question. Yes, the wood has to be drilled. When I bought my restored TR3B, the PO bragged that "the sidecurtains had never been installed." No wonder! He COULDN'T install them! New wooden blocks were installed in the resto, and they were not drilled out to make room for the Dzus "screw."
So, I drilled them out. One bit of information I learned that I can pass along to you. YOU CAN DRILL THE HOLE WITHOUT REMOVING THE UPHOLSTERY OFF THE PANEL. Once you have decided exactly where to drill the hole (no small task in itself!), mark the center of the hole with a scratch awl. Using an Xacto knife, I cut an "X" across the hole for a width of 1/2", east-west and north/south. This allowed me to peel back the upholstery far enough to fit in the drill bit and start drilling. I was very nervous, as I had no idea whether or not the drill bit would catch on the upholstery and make a mess.
It may have been dumb luck, but it worked. The nice thing about it: when you put the bracket back on the panel, you cannot see the hole anyway.
Good luck.
Phil