Hi.
I would say it is not very precise to state that no losses were reported by the day-fighter units on this date. A more precise answer would be no day-fighter losses in this theatre.
However, I am not entirely sure that even this sticks, as several of the units I usually connect to the war in the desert did in fact note losses on September 9th 1942. If any of these are in fact connected to the loss described here is an entirely other issue...
There are 17 losses noted for the 'ordinary' fighter units on this date, but none of them seems to be fitting your description.
The only one for OBS that is a slight possibility is this one:
http://www.ahs.no/ref_db/lw_loss_pub...?lossid=112119
However, I have not checked were this location is, but at least part of the unit was detached to North Africa in the dates surrounding your loss date.
It is of course possible that the aircraft was Italian or from a Jabo/Schlacht unit.
Regards,
Andreas