I talked to Mark Johnson, Cole's brother yesterday. While Cole's death was unexpected, he did have a laundry list of health issues with which he was dealing. The cause of death was heart failure. The family is not having services for Cole, as his vast network of friends, mostly fellow fans of popular culture, are scattered all over the globe. Your condolences, though, are sincerely appreciated by the family.
A very short obituary is in the Bucks County Courier
Here are some more of Cole's delightful envelopes. The first one is a really obscure reference to totally wacky cartoonist Eddie Eksergian, who had a strange obsession with umbrellas.