ZS MK2 Numberplate Bulb holder

[ZS]

Before I give Rim-yer-brother's my hard earned... Has anyone got a couple of MK2 Numberplate Bulb holders?

Rimmer's say this is the correct one: http://www.rimmerbros.co.uk/Item--i-XFC000160

But it doesn't look anything like the units I have sat in my bumper... then again the units i have don't fit! They just fall out and I can't do anything with them like changing bulbs etc...

Further, I spoke to my local MG Rover (ex) Dealer... who said it was a good part number (XFC000160) but since the picture is generic and my numberplate is listed as a MK1 (but only for the rear!!) he can't guarantee it will fit... - Do I risk ordering the wrong part???