Besides the surprise that that you found a shop to touch the bindings back when they were new they would mount bindings a couple ways.
1. The toe of the boot would be placed at one half of cord length of the ski. Take a string and measure from tip to tail, fold it in half and place that length from the tail to the point of the boot toe.
2. Stand the skis base to base but no pressure against each other, mark the spots that the edges touch each other at the tip and tail (these are the contact points). That will be the length or the running surface, place the ball of the foot/boot at the half way point of the running surface length.
If you compare the two methods the spot will probably be very close.
3. Depending on the vintage of the ski on the side wall by the serial number and length markings there may be a little triangle with the point facing up to the top surface of the ski. That might be a toe point mark for the boot.