I was reviewing some pages on my site and came upon one that shows at least some of the different bearings used on different models; include both mk1 and mk2 TD125 models.
The TD125 saw a re-design of its bearing housing when it evolved from mk1 to mk2. The mk1 has a cast aluminum bearing housing that bolts in to the massive sub-chassis by means of 3 machine screws. The mk2 has a different style of bearing housing that is much less massive in external dimensions, although internally the same as its predecessor, and is pressed in to the same subchassis.
Neither mk1 or mk2 allows replacement of bushings or thrust.
Here's a link to that page:
http://www.theanalogdept.com/td_platter_bearings.htmI don't have much information on models like the TD320 or TD2001 but there are scraps of info. Here's a link to a page with a brief interview with Rolf Kelch. Rolf was in upper management at Thorens during the nineties and oversaw the product evolution during that period. He has some comments about the different bearings used in the TD2001, TD320, TD520, TD126 and also the Thorens Ambiance. Also there is commentary and some photos of bearings produce by a company in Germany called ClearlightAudio. They were and still are Thorens modifiers and did produce an upgraded version of the Ambiance bearing that was made available to various different models of that era.
Here's the link to that page:
http://www.theanalogdept.com/rk_125_6_sub-chassis.htmI hope this helps to clarify some of the misunderstandings in the above posts.
-Steve