So I found this interesting article on E! online

October 1, 2003
eonline - ask marilyn

Dear Marilyn: Was Mister Rogers a U.S. Navy Seal?
Amanda Handshue, Seville, Ohio

Dear Amanda: The urban myth casting gentle Fred Rogers of children's
television fame as a military superhero dates back at least 10 years.
In some versions, he was a great sniper in 'Nam. The Navy Seal story
is a newer version of the myth, which claims he always wore sweaters
to cover an array of macho tattoos on his arms.

Fact is, Rambo Rogers is as much a fantasy person as the King Friday
XIII puppet in Mister Rogers' Neighborhood of Make-Believe.

However, the beloved late performer did have another life--he became
an ordained minister in 1963. He started his career in broadcasting
as he was earning a bachelor of divinity degree.


So it would seem that our beloved MR. ROGERS (or as my dad used to call him Mr. Ogers) was no Navy Seal, just a friendly neighbor and ordained minister.