MY Idea was to have a Key to open the oil and case plug! I used a 1x1/4" OD. aircraft washer with a 7/16" hole in it. The washer is 1/8" thick! carry it on my Key ring, fits great in the slots! you can use about anything that fits in the center to turn the Cap lose! Works like a Charm!
NOTE: It has to be a very good grade of washer. The only one I could find that would work and last was the Aircraft type, and you have to drill the key ring hole with a Cobalt around 1/8" or a little bigger! Most aircraft washers are gold in color and very hard.
Thanks Virg, Delphi Drifter Forum.