FK-12 Comet - Can you help ?

I am trying to identify the construction number of a French FK-12 Comet - I have been in contact with the owner and he has identified this aircraft as having had three previous French registrations.

The aircraft was built in 1997/98 and is believed to have been the first FK-12 Comet sold in France - the registrations are

1) 28-BI - the aircraft was painted silver

2) 73-KD - the aircraft was painted silver with lots of advertising text - See Link B for photo

3) 77-ALK - the aircraft was re-painted light blue and yellow

4) 25-UA - the aircraft is still light blue and yellow


Here it is airborne over the Besançon region - thanks to C Alabouvette



My guess is that this aircraft is c/n 3 or maybe c/n 11 or c/n 13 - can you help resolve this query please ?