(click
photo to see the TD166 manual at analogdept.com)
This is the original photo, when I bought it via ebay
First I removed the complete inner mechanical stuff for variyng the
speed etc. Then I
build a new frame out of solid beech and veneered it with
bubinga and stained it in mahogany. The bottom is a 3 layer
construction
with plywood-MDF-plywood. The middle MDF layer has drilled holes of
35mm diameter. This holes were filled with sand before the 3 layers
were glued together.
Other mods:

A metal inner plate instead of the original plastic one. As you can see
here it is filled with elastic sealing compund for better resonance
damping.
Furthermore I bought parts from a LINN LP12 before doing the circus
upgrade. I kept the springs and build them into the Thorens. Also I
kept the armboard to "prettify" my Thorens. The rest was resold again.
After all the Thorens got an acrylic turntable mat.
The AS212 was equipped with a high output MC Dynavector 20B.

(click photo to see some
technical data of the arm)
Feel free to contact
me, if you have any questions, suggestions, comments etc.