It seems that BT headset info is stored here. Not sure if this is all, but it is a start.
Code:
[HKEY_LOCAL_MACHINE\Software\Microsoft\Bluetooth\Device\0003897e0e8e]
"trusted"=dword:00000001
"class"=dword:00200404
"name"="PLT 510"
[HKEY_LOCAL_MACHINE\Software\Microsoft\Bluetooth\Device\0003897e0e8e\Services]
[HKEY_LOCAL_MACHINE\Software\Microsoft\Bluetooth\Device\0003897e0e8e\Services\0000111e-0000-1000-8000-00805f9b34fb]