onehundred80,
If you're talking about the stub key part in the ignition lock cylinder eBay link above, I believe it does match the fob key part, it you drive out the roll pin and separate from the pivot casting. It seems to be consistent with that shown on page 13 of the "How to take apart a Crossfire key fob by tom2112" pdf. That key part might also matches what was delivered with my salvage lock cylinder (center of https://www.crossfireforum.org/forum...ly-tumbler.jpg ).
The cylinder eBay photo is lousy, so slightly tough to confirm, but that stub key should be Mercedes/Chrysler fob-compatible.