All F3A-1 Corsairs had the same wings as their contemporary FG-1 and F4U-1 counterparts. In other words, all Brewster-built Corsairs had outer wing panels with fabric covering the top and bottom behind the wing spar. The only significant areas not covered by fabric behind the wing spar are the wing tip section, and ammunition bay areas. Fully metalized wings did not start appearing until some time in the F4U-4 production run. I hope this helps.

Cheers,
Richard