Just came across this June article.

Posting as the lone CDN article I could find from back when, the Star in 1982, identified him as having worked in radio ad sales, at a station his father in law was an executive with. Unfortunately, neither that article, this below or a 1982 St. Pete Times article give more details on that aspect, ie, where, if this was his career or just a brief go-round, who the inlaw was.

Interestingly, it seems posters from Websleuths did all the lifting in putting 2 and 2 together for Miami-Dade that they had a contemporaneous John Doe similarly described as the Pinellas report. Will reserve comment on that: https://www.websleuths.com/forums/threads/fl-miami-male-multiple-20-45-yellow-metal-pink-sapphire-ring-up54159-nov-3-1980-ronald-gilchrist.680699/

https://www.miamiherald.com/news/local/crime/article276446786.html

On Oct. 28, 1980, Ronald Gilchrist left his parent’s winter home in Clearwater to drive down to Miami.

The 29-year-old drove his in-laws’ blue 1977 Ford LTD to spend a few days in South Florida before he had to pick them up from Miami International Airport on Nov. 3. He was supposed to help his in-laws move into their new Marco Island condo.

But he never made it to the airport....