I just made a new switch for mine, and it works fine. (mine looks to be about the same years as yours roughly).
To eliminate the coin mech, I put jumper wires in the plug, I put a wire in each socket.red wires(#1,#7 together) black wire(#3)
Might be different on yours, but I think that is the standard numbers to make it vend with out the coin mech. I used a door bell, but any switch will work.
If the lights come on showing a product is out, I'll bet it will vend like this, or else buy the free vend relay i told you about.
vend relay link
http://www.chicompany.net/free-vend-relay-no-modifications-to-machine-648.htmlOther wise this is a link on how to make it vend with no coins.
http://soda-machines.com/discussions/index.php/topic,871.0.html