Well, not a "real" trifecta since you only have to win once- final high bid wins all.
Up for auction is a single trio

of Post Cereal Mantles in various forms of conditional pleasure.
The 1961 is the company issue: they were team sheets you had to send in for and cards were separated by perforation (as you can see in the scan). The cardboard stock is thinner than the cereal box. One 62 is hand cut from a box and the other is from the 1962 Life Magazine insert. Since they are all raw you can fondle them all and test their own individual uniqueness and even give the ol' smell test.
Opening bid is $20 and continues in bids of $2 or more whole-dollar amounts.
Bidding ends Sunday at the final timestamp BEFORE 11:00pm EST.
Shipping is $3.
Payable through PP f/f (preferred), but USPS MO or MoneyGram MO or personal check or cash are also accepted, (or all four forms simultaneously).