I went to a reunion of old picking buddies and some folks I'd not met were singing songs on Tom Shepard's cabin porch when we stopped by to say hey. Tom handed me his guitar saying "len's been known to pick a song or two" and reluctantly I did (unless I warm up, I have vocal control issues these days, so I don't like to do this). After some kidding from these folk, I played one of mine, Mandy Blue, because I can actually remember those lyrics.
When done there was a discussion about my voice and these folks all decided it was Marty Robbins. That's no insult but nor is it particularly true. My thought was they keyed on the song being a sort of tex-mex mariachi which it is. The studio version is even more mariachi but I get what they said although I don't and wish I did have a voice like Marty.
That sound is associated with Marty but is really the sound of the Glaser Brothers who were the session players and backup singers on many of Marty's hits. Also, they were one of the unsung groups who founded the so-called Outlaws who tired of Nashville slick and went their own way. While carefully copied by others, they were an original sound more derived from cowboy music (thus Tex-Mex) than what prevailed in country at the time. Here they are in their last performance in 1990.