Artie, I guess you mean 'vintage' in a bad way. Anyway, according to the serial number, it's an early 2006 iMac:

https://support.apple.com/kb/SP35?viewlocale=en_US&locale=en_US

Apple Sez:
• Built-in Bluetooth 2.0+EDR (Enhanced Data Rate) module

I don't understand why it was all working fine until big bad new iMac came along. I did have someone move the wireless keyboard and mouse it was using back to where the new iMac is, and they are not linked to the new iMac's Bluetooth. It may just 'come back' when I wipe the drive and install a new system for the kiddies. Just gotta get a copy of the drive over to a partition of the new TM drive for the new computer, as per this string:

http://www.finetunedmac.com/forums/ubbthreads.php?ubb=showflat&topic=4991