727 id made / possible to narrow it down further?

I can just about guarantee you it's not an OD

This is a 727 VS A518/ 46RE

My research shows you cannot put a 727 based OD in without cutting up the tunnel and highly modify the crossmember



The OD has the same shift pattern as a conventional Torqueflite, the OD is electrically shifted

I don't understand where you got that "chart" from, it says something about "lock up?" That is a whole different animal.