Argh.... The 9th AF was in the ETO...
Like I said, my mistake. And my apologies.
As to when the P-47 ceased production.... The Last N models were delivered in December of 1945...
Production canceled in August at war's end. Last aircraft came off the production line in December.
As to the speed of the 109G-6/AS...
Performance of the Me 109 G with DB 605 AS.
Test Report Nr. 109 20 L43
Date 22.1.44
Copy 4
Dept. Flight Testing
Group Performance
1.) Speed at sea level: 315 mph
2.) Speed at FTH: 406 mph
3.) Full throttle height: 27,231 ft.
And this:
(Image removed from quote.)
Let me just repost that image of yours...

Quite right. 405 mph at Kampfleistung. At Notleistung its speed would be about 430 mph.
That chart shows 648 km/h at Kampfleistung. That's 408 mph.
That chart shows 690 km/h at Notleistung (MW50 Leistung). That's 428 mph.
That's performance similar to real-life K-4s. In AH we have the best possible version of most aircraft flying with closed radiators and polished, waxed surfaces. In real life you'd be hard pressed to find a 450 mph 109 anywhere.
Kampfleistung: Combat power/max continuous power (usually limited to 30 min).
Notleistung: Emergency power. Allowed duration varied between engine models.