Conclusion:
So first of all I have to thank Bill Reilly at RMS for some of the best customer service I've received...ever. I sent a message to the "contact us" link on their web site and had a response in an hour and a half. After hours on a Friday I think! Very Cool!
What happened to the original? It looks like the metal sleeve was too long and hung out beyond the bushing. so the individual that installed the UCA "created" a spacer to deal with it. Their choice was to cut the ends off of the old rubber bushings and then used whatever washers they had to fill the gap between that and the frame. Only of few of the supplied washers were used. The result was movement. Back and forth at first against that rubber I suspect. Then up and down as the bushing got egged out, until one of them disintegrated.
I admit the car felt a little sloppy for some time, but only when I passed someone and crossed the crown in the road at speed. The clunk at intersections on the last ride was the coup d'grace to get me to investigate.
lastly, keep receipts ya'll! identifying aftermarket stuff is hard and going to become increasingly difficult. Things wear out even when installed correctly. No more going to a parts counter anymore.
dw