Would it be related to the McLoskey shipyards in Tampa?

That's the only thing (besides, I guess, MacDill AFB - during WWII, Southeast Air Base) that'd be near Dunedin as far as I know. McLoskey built concrete ships there... so no steel, but they'd be using landing vehicles in the South Pacific. Oh, and there was another shipbuilding operation there, major economic stimulus... I think it was called the Tampa Shipyard.

There were training grounds for beach landings on the beaches near Tallahassee (Carabelle) and Miami Beach... and I think Key West. But none of those are really near Dunedin, either.

In the 1940s... Dunedin would have been pretty rural and agricultural. There were some phosphate mining & refining operations in that part of the state... was phosphate something steel production or vehicle assembly could have used? Most of that goes to fertilizer nowadays... and associated deposits of limestone are used to make cement and concrete.

(Oh, on the steel in the northeast, the reason Birmingham, Alabama, was named "Birmingham" was because of the steel industry hoping to recreate the English city in the American South. But that's nowhere near Dunedin, FL. )

I'm curious, too!