This is really a prototype until I find a nice 'classic' handset. Just some friday afternoon nonsense in the office.
Step 1: Dismantle
Moto headset: First make sure it works, from here on in your warrantly is awol. Open it up as per the related instructable. Desolder the earpiece, its weak. Tweak out the mic with a plastic tool, dont damage it.
Step 2: Wire & Setup
I soldered in the earpeice, polarity is not an issue. If you do change the mic bear in mind you'll have to match it with similar characteristics & polarity.
I dremeled a hole for the charge and hot gluded the pcb in place.
I also put a light pipe in for the blue status LED.
Step 3: Put Together and Test
Any questions, put them in the comments and I'll answer them - thanks.