[TenTec] Another PTO rebuild question: Where does second pin go?

[Andrew Moore]

Two small pins (about 1/4 inch long) were supplied with the PTO kit.  One is
the stop pin that goes through the PTO tuning shaft's threads to stop the
PTO turning and going too far into the PTO coil.  I've installed that and it
works fine.

The other appears to go through the "core drive rod" (part 90202), but it
goes in only so far (about a millimeter) and stops, I'm assuming because
it's hitting the tuning shaft (90201) which isn't drilled to accept a pin --
it's solid.  However it looks as though it could travel about another 1 mm
before hitting the tuning shaft.  Maybe there's another axis, drilled to
accept pin, that the CDR is supposed to lock to...?  ...which might be why
the instructions said to take note of the position before removing the pin
:)

Any help would be appreciated.  I've lost the disassembly photos that I took
when I began this project.

I have a photo of the (started) pin I can show for context.

--Andrew, NV1B