From the 50s here's a two piece linen bathing suit or sun suit.  Plunging neckline that does up with two self-covered buttons. Both the top and panties are totally lined in white cotton. Long metal zip at back and two self covered buttons that do up at the front.  It has the kind of adjustable straps that crisscross on the back which button up to the suit.  There is no label. 

Top: Bust 36" Waist 30" Hips 36" Bottom of the top 40"

Panties - are navy blue linen... Hips: stretch out to 34" & length is 10

It's in excellent condition.

Great pin-up suit!