OK, just got off the phone with Jerry at Professional Drum Shop in Hollywood. I've been visiting there for decades. A great place to hang out! I'll sum up what Jerry told me:
Pearl did, in fact, try to get Buddy as an endorser around 28 years ago, which would be about 1983. Two kits were made for Buddy. The tags on the drums only said "All Maple Shell", which was just before they began to market them as MLX, BLX, etc. The first kit, with a 16x26 bass drum was played by Buddy at an Academy Awards show or something similar. Buddy didn't like where the tom mount on the bass drum was positioned! You know Buddy with these things! That kit was at Pro Drum, but "disappeared" shortly after and is most likely in the hands of someone in Florida. The second kit, which is the one up for sale on CL, was never played by Buddy, but was made for him. Yes, that second kit has a 16x24 bass drum. Each kit contained only one floor tom at the time. Jerry informs me that this kit was sold to the first owner for around $1000. The second owner is the one selling the kit on CL.
So, it appears that Pearl did try to entice Buddy over to them! I'm glad to know that Buddy really dug the beautiful RK kit from Joe MacSweeny of Eames Drums.