As a rough guide you can say the older the flatter. Somewhere someone has G F Handel's old tuning fork. It is well flat of modern pitch. Northumberland Small Pipes consider themselves to be in the key of G. In modern pitch terms they sound anywhere flat of F# to sharp of F. It is possible to make a chanter that plays in modern G but as the pitch goes up the spacing gets tighter.

The truth is that agreed pitch has risen over time. In the UK the convention is that A = 440 hz. In Germany I believe it is higher. Conductors find that if they raise the pitch the music sounds brighter so over time it rises. It must be hell for singers.