I happen to have a complete spare (4th) Key Fob assembly, but with a bad circuitboard from a leaking battery. The RFID and hard key are fine and I'll harvest these for a minimalist rig.@Left Field
In regard to the soon to be offered, THREEDOM, RFID+keyholder ....... it is a key holder made from "Durable Engineered Plastic ", that has a small pocket so to speak.... where you place the programmed RFID chip taken from your stock fob into it.
With that said you buy the RFID+keyholder from THREEDOM, attach your stock key to it, place your RFID chip into it's chip holder and you are ready to go....
OH .... your cut key blank will probably not fit the RFID+keyholder... unless the blank/the end of the blank key is shaped, etc. exactly the same as a stock JL/JT key.