I had the K-Line collector's club GG-1 electric engine. It had the connector for TMCC but no other parts or hardware, I would have had to add all TMCC electronic stuff(circuit boards and whatever) to include speed sensors and speed sensor tapes on the flywheels at the motors.
See if you can look inside the engine and see what it has or doesn't have, before buying it.
As far as I know the old K-Line engines needed everything for the TMCC upgrade and were not plug & play compatible. I could be wrong but I think you will be spending a lot of money to add TMCC to that engine.
Clue to buying a TMCC equipped engine: if it says TMCC ready it has only the TMCC connector plug(nothing else!), if it says TMCC equipped then it has the full TMCC with it. I learned this with H.O. DCC stuff, and I would venture to say that TMCC is the same. I do some H.O. as well at times.
Lee Fritz