This site has every kind of power cord imaginable. Have fun scrolling down through. There are some cheater cords down there. I know I have seen them elsewhere so will post again when I find them.
http://www.kenselectronics.com/lists/pwrcord.htm
Edit: Ken provides this note: SCAN-AC Rectangular, Tokuden TS-031 16x8MM, 8MM=.310" center spacing, .108" holes $4,50
SCAN-AC fits 1950's non-polarized TV cheater cord sockets; old Heath SB-301 & SB-401