[Juha]

Hello John
Not a bad translation. Some clarifications (hopefully):
Paikallishistoria = local history
Maakuntaahan is used to remote back country of our country…, maybe better to say: The county/province is usually thought to be a remote back country of our country which acts of war had not threatened. However our air wars have had significant impact on the building, development and use of the air field.

reliance on military aircraft Mäntyluotoon. Maybe better : Military aicraft were based on Mäntyluoto.

Ilmapuolustus = air defence
brought traffic and cargo box of the city. Better: bought a transport and freight airfield to the town.
against the field, moved to a military purpose. Better: transformed the airfield to military airfield

Satakunta was a continuation of the war... Better: In Satakunta there was during the Continuation War…
That time is dormant in the province. Better: Inhabitants/People of the county/province have/has kept silence on that time.
The war ended in the destruction of the German airport of departure. Better: At the end of the war when leaving Germans demolished the air port.
Ye-Colonel , Ye = General Staff