Ultimately I had to re-solder even my solder repair job, and in the process damaged a coil of wire on the circuit board [doh!] such that the fob wouldn't transmit to the car.
I bought a replacement key from my stealership. They didn't need two keys to program it, just $200!
2005 300C BRILLIANT BLACK, DRL, Mesh Grill/Vents, Chrome Pillars & Fender Trim, MDS Indicator, Quad Brake Lights, Tinted Windows, De-Molded, K&N Aircharger, 180 T-Stat, Flashing Sidemarkers, Predator Cust. Perf. 93 CAI Tune
1997 MUSTANG COBRA 'VERT, TRIPLE BLACK, Vortech S/C'd., ECT Mod., 4.10 Rear, 18" Saleen Wheels
1950 FORD TUDOR FLATHEAD V8, FLAT BLACK, 54 Chevy Grill, Nosed/Decked, Frenched Headlights, Air Shocks, Three-On-The-Floor w/OD, Dual Glasspack Exhaust, Dual Two-Barrel Carbs