I've also got one that needs replacing -- it completely crumbled and fell off. Kinda seemed like dried out leather, but was hard to tell in the state I received it. If anyone has a source and/or replacement instructions, I'm all ears.

I've got a late 1973 early 1974 Slingerland #190 BR/TDR in my Buddy Rich snare drum collection and the bushing is still in place!... certainly rare as most of 'em have indeed disintegrated over time as they are...

Rubber! UV and age take it's toll over time. So, what can one do? Hop on down to your local hardware store and/or HD/Lowe's and look for the rubber tubing that might be used for "gas line" on lawnmowers, wackers, etc. The ID is about right for a snug fit on your TAS.. ( tension adjustment screw ) .. and in most cases you won't need the little retaining washer that holds the original in place. The rubber they have will most probably be BLACK, but that is of no matter as Slingerland did use BLACK as well as BROWN over the years. Cut to size and install! The OEM piece on my BR/TDR is BROWN... but I wouldn't hesitate to change it out when it's time comes. I'll attach a pic!

Tommyp