Hi Craig, yes, seen your pm and will get something sorted asap.

As I said the serial numbers on mine are 4BO 035 111A so very similar to yours. I THINK the first few letters and number are an ident for the vehicle they are designed for but I could be wrong on that....perhaps someone else knows the coding?

Happy to send to you so I'll be in touch tomorrow sometime hopefully,

Cheers, Frank

I found this helpful when considering oem headunit options for the 90:

http://www.ibiblio.org/tkan/audi/radios/radios.html

It would appear Franks changer is for the later (A series) Concert setup not the Delta CC?:(