[Ludovico Slongo]

First of all, thank you very much Andy, Hakan and Ferdinando -altough with a lot of things still to clarify (I agree with you)- some new (to me) pieces of info has come to light. After receiving your info I went back to my books and I collected some additional pieces of information. Inside the classic history of 4° Stormo: "Quelli del Cavallino Rampante" -the source from which I extracted the description of the combat- I found that, back from the above mentioned combat, Reiner received order to retreat to Rome-Ciampino with his men, it was 18.00, an hour still consistent with a previous combat at 17.15 (even if I really don't know if the Italians and the Allied used the same timeline to record the hours of their missions).
A second data was that during the day additional P38s were claimed at unknown hours and places by Oblt. Frielinghaus of IV/JG 3 and Obfw. Johann Pichler of 7/JG 77 -this was extracted by "Spitfires over Sicily".
Here it is extremely interesting to see if the Messerschmitt's claims could better match the only known (thanks to Ferdinando) American loss and I hope that Mr. Cull or some other Luftwaffe expert could help. As a very last note, I took a map of Sicily where I could see that even if by ordinary road the distance between Gela and Agira is in excess of 100 km, in straight line the distance is 74 km (Agira is NNE of Gela) so a place 15km north of Gela is around 60 km from Agira, possibly still too much ... However thanks again for your help.
Ludovico.