I need some advice on mirror fitting on my 1998 B5 S4 and Im sure the expert is on this forum somewhere

Somebody recently hit one of my colour coded plastic mirrors in a car park and cracked it (no note or anything). Anyway I quite fancied the 'bling' metal mirrors and managed to find some on ebay. The guy said they came off a 98 S4.
As it was sunny at the weekend I thought id have a go at fitting them but having taken the old mirror housing off and comparing it with the new metal cover there are some subtle differences. The screw holes that hold the internal mirror gubbins to the cover are placed differently and also the black plastic panel at the bottom is a slightly different shape (more angled at the external end, the metal one looks squarer) and lastly the glass is a slightly different shape.
So it seems i have the wrong mirrors, maybe the metal ones are from the newer facelift ? At this point should i go looking for the internal bits (motors and such) from a newer audi A4 so i can use the metal covers, if so what am i looking for ?. Or should i give up and put them back on ebay ?
Cheers
herbie