I had the same problem in my 93 SC400. Tried 4 different products, with very little result, same as you!
I ended up taking out the glove box then the Airbag module, to unscrew the wood trim.
Easier to buff without hurting the leather around the trim!!!
The polish I used was Turtlewax Polishing Compound, Scratch Remover paste. The white paste type,
with a variable speed Elec. Drill and a sheep wool bonnet.
Total time about (2) hours of tedious stuff.
Now I don't have that eye sore I use to see every day I got in my car,, :D
I will try to figure out how to upload pic's to show you how mine turned out!!