Due to the difficulty of finding replacement ring gears at a reasonable price for the Mazda auto tx flex plate I suggest we use the current flex plate and merely tig weld the damper to it.
Your current starter is sure to still fit and work.

I was quoted ring gears $95 each from a company in NZ with $95 shipping by boat. No telling how long that would take.

Mark Steitle brought up the issue of room for a thrust
bearing between Tracy's spline flange (brown in the 3D)
and the PSRU adapter plate. Simple solution. Reverse it.

That gives more than enough room for a thrust bearing.

Here are the 3D's.

Some of the 2nd gen current flex plates have large holes near the
center that weaken them. The solution is tig weld in a plug.
The 3rd gen did away with the holes.

I just bought a 13B auto tyranny flex plate on ebay for $12.
Shipping and handling was $30 :)

Lots on ebay for $50.

Paul Lamar