I came of age in 1990's rural Kentucky, which I suspect that would be about as equally "redneck" as Florida at the time of this individual's death.
People, especially gay people, would kind of just "know" who was gay without anyone having to make some sort of formal announcement. There were only a couple "out" people at my high school. The rest of us just kind of kept our mouths shut, basically to avoid any kind of stigma being attached to us.
After graduation, some of us stayed around. Some of us went to the bigger cities, even if merely to Louisville a couple of counties north, where gays had more of a presence. The others, who knows?...
That being said, I honestly don't think I know a single transgendered transgender person. I know several folks that cross-dress (or whatever you'd call drag-queenism) for drag contests at the gay bars in Louisville or for parties and such. But nobody that does it in "everyday" life.
I think it's important to keep the M-to-F part (meaning stressing the "male") and that it is necessary.
There are plenty of people who just kind of "drop off the face of the Earth" once they reach maturity, or run away from home.
Such individuals were almost certain to have been looked upon as "male" at that point in their life. Those recognizing them as "female" would likely be from closer to their death. And nobody's really recognized them from that period. Either that or they didn't know their true identity.