This is an RCA 77-D MI-4045-D that is in excellent condition all
I did was re-paint the body, installed new grill cloth, 7 ft cord, conector,  
and new ribbon. Every thing else is original and in excellent condition. It is wired for 250 ohms.

RCA 77D MI-4045-DRCA 77D MI-4045-D

RCA 77D MI-4045-D

As you can see below the windscreens are not dented like most.

RCA 77D MI-4045-D

RCA 77D MI-4045-D