That would have been my guess. First Topps base for him…I think he’s in the ‘85 Traded Set as well though, in fact why do I say that knowing what site I’m typing on…Yes, 64T.
But still, first base, you get his first season with the team stats on the back, and for whatever reason the year of release, championship year, tends to have more resonance than images and players that line up correctly.* Plus not only was he a key contributor, but is one of the top at his most played position, 3B, in franchise history, and inducted in the Team HOF last year. So he has earned being very popular within the fanbase, and certainly his ‘86 base is a “key common” to pick up.
*ie the 1986 Topps Mets set includes Clint Hurdle and Calvin Schraldi but not Bobby Ojeda and Kevin Mitchell. In addition, the 25th Anniversary of the franchise uniform patch the Mets wore in 1986 being no where in the 1986 Topps product, but all over the 1987 product.