I don't collect them, but I have been bothering people to answer some questions, and your tickets confirm some queries I had about my Secretariat Triple Crown Belmont ticket auction. My auction is here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2795339213&category=429&sspagename=STRK%3AMESSE%3AIT&rd=1

Since Secretariat's number was 2 in this race, and the bet was $2, I was unsure about some things. Here is the ticket:

Your tickets (the same year, 1973) confirm that the TWO's along the sides are the money bet on the race. The 2/TWO on the bottom is the horse number. I still don't know what the EQUN is, but am told it is just a security code to thwart counterfeiting. So all this proves that the ticket was bet on Secretariat -- the #2 horse in the 8th race on that day at Belmont was Secretariat -- see the program below. Hooray.

Thanks again,
Robert