I have an issue with he autostick I recently put in. After about 200 miles it started making an awful knocking sound. After further diagnosis and rechecking bolts etc, I have isolated the noise to the transaxle. I suspect the torque converter has kakked itself as the car sounds normal in idle, but when it goes into any gear starts knocking - even at idle.

I do recall when I reinstalled the motor I had inadvertently misaligned the TC splines and tightened the engine up on it. When I turned the torque converter to do the flex plate bolts up the engine "clunked" into place. Fortunately I have a spare TC.
Does anyone have any experience with this and does it sound like I am on the right track?
Can you get faulty TCs rebuilt or is there a suitable replacement? Any help and commentary much appreciated.

Sounds like I will be honing my engine remove/refit skills again soon

Yes,
unfortunately the torque converter has had its day....
I did the same thing a few years ago...

if You do drive it like that... You are likely to loosen all the rivets around the centre of the flexplate..
depending on how bad the internals of the torque converter... Yours doesn't sound too bad...??

Torque converters are usually just replaced... and not cut open and repaired... but Ours are in short supply...

I repunched the rivets and spot welded the flexplate in 4 spots..
still snapped the welds and loosened the rivets again...
ended up replacing the flexplate too...

I had had the torque converter in & out many times without any problems... Until I turned one of the axles...!!
which moved the splines....

You need to turn the Torque coverter as You push it onto the splines.. If the flexplate bolts are too tight... then they are bending the insides of the torque converter..

hopefully Your flexplate is still OK.... check the centre rivets...

cheers

LEE