I found some confirmations about Freytag's tally:
1st official victory: third week of July 1941, a Mig 3, same for his second one. At the end of July, had 5 victories, with three I16 to add. Ace in two weeks, after two years in the Luftwaffe!
20 victories in October, 26 victories in November. 35 in april 1942, 40 in May, and 50 in June.
57 victories when he arrived in Sicily, in the beginning of July 1942.
Had a G2 in Sicily, and in africa after that, beginning in the end of october 1942. Still had a G2 when he landed wheels up in Tunisia in april 1943.
he could have flown a Macchi as a test when JG 77 tried them in 44 in Italy...
Could have flown a Me 262 in april 1945 with JG7, but I have no confirmation (pic, document...)
best regards