Is each headunit keyed to a specific pull-out facia bit? Which part of the head unit is the keycode stored? On the pull out securtiy facia or the actual head unit?
The reason I'm asking is because I lost the little security facia bit for my 7000 CD model, but it didn't bother me as I already had a new head unit to put in.
But now my mate (who has the 5000 tape model) is interested in buying it off me but was wondering if the facia bits will work (I still have the 4 digit code for mine and he has the 4 digit code for his) if we swapped them over, or will someone have to go to Ford and order a replacement one for the 7000 model?
Cheers for any help.

Why don't you swap em and find out?

Bit of hassel for my mate, he doesn't want to try it without knowing for sure if it will work.
Any ideas on how much a new secirty facia is (I might sell him the head unit 'cheap' and say its his responsibility to get the security facia)

Don't hold me to this but I think the panels aren't "tied" to the head unit and as long as you've got the code you will be fine with a replacement panel.

shall try it with the missus fester and my ka tomorrow and shall get back to you with what works..or doesn't!

It is the stereo unit itself which is coded, not the removable panel(if you mean the smallish one numbered 2-5)
However you have to use the panel from the correct series.
i.e. a 5000 series stereo will only work with a 5000 series panel.
A 4000 series panel will be no good.

Any joy with that Fastka?
I think (off hand) my unit was a 7000 and my mates is a 5000, but the security facia (yes, that annoying little bit numbered 2-5) is the same shape/size.
I might just take the bullet this weekend and take my head unit over there and have a go (And retrive my CD that's been in it since I took the head unit out :))