[Milsurplus] Need AC power cords with round chassis "pins"

[radioman390 at cs.com]

 I have been buying some 70s era electronics on EBay that has a computer type AC power cord, except that the chassis receptor has three round pins instead of the blade-=type on current equipment. Also the shape requires rounded edges on the female.

Does anyone know the designation for that shape of plug: I tried going through Newark Electronics webpage but unless you know the name/style, they can't help.

These were used on Racal receivers, and on ealy Belar FM monitors.

Thanks