Chuck,
As a point of info, JetCat P-120 RPM sensors are optical....not Hall Effect.

Jon,
Why don't you call Bob Wilcox at JetCat USA for an estimate for the engine core repairs, and buy an installation kit from him? It includes all of the stuff you need for around $900.00
You could could probably be back in the air for around $1500.00 or so. That's lots cheaper than the price of a new or used engine.

In the end, should you eventually decide to sell it, it is worth allot more complete with all JetCat parts, instead of being "*******ized" with parts and pieces from all over. It would be easily serviceable too. Just my humble opinion.

Harley Condra
BVM REP
JetCat REP