have finally fitted the solid mounts to the rear subframe, had to pull the motor but not the 'box (needed to do a flywheel oil seal anyway).
finished assembling it on Saturday and took it for a short run.
I still believe i have my underlying problem (this wander business) but
think it has reduced (but i thought that before with each tweak i did!)
For the record, for anyone building a hi-po/handling beast Type 3, changing these rear sub mounts is a must i reckon, the stock ones were in great condition but are very soft. I know there is a couple of guys doing coilovers on their type 3's so worth considering.
As for me.... well back to the drawing board, think i'll start looking at the front setup.
Angelo