[Storebror]

In UP 2.0 the dates for the F-84G1/G2 are 1948, where in
the HSFX 4.1 the dates for the F-84G1/G2 are 1955.

AFAIK the F-84G entered service in the 1951 and got retired by USAF in mid 60s.
If that's true, 1955 would be historically correct, whereas in 1948 only F-84A/B/C where available.

Best regards - Mike