There are elements that make this couple sound more transient (ill-fitting clothing, although plenty of people don't wear the size they might by measurement), but the rings throw me. They don't sound expensive, but they're nicer than someone in tight circumstances would have. Real gold, real diamond. I suspect it's something like the Jimmy Hendricks/Kim Mills situation, where the couple might have good reason to leave, and their families assume that that's why they're gone. It would go along with the less than professional tattoos (I agree with those that think that his cross more closely resembles a swastika). I don't know why they would have been killed, though. I assume a robber would take jewelry or watches, although perhaps they weren't thought to be real/valuable or maybe there was something else that was the primary target (car, cash, drugs).
The absence of shoes makes me think of a trucker. Supposedly truckers will make someone take off their shoes before getting in a cab.
I saw it suggested earlier that they might be Martha Wes Dunn, 15, and her boyfriend Eric Glenn Owens, 17, who disappeared in September 1990 from Daingerfield, TX. They were thought to be heading toward Haworth, OK, and were seen in Durant, OK, both of which are 1-2 hours south of where these UIDs were found. They were said to be heavily into drugs at that time. I can't say that Eric, in particular, closely resembles the reconstruction, although he may have matured from when his photos were taken. I have no idea why he might have an R tattoo. However, Martha is noted to have a pointed eyetooth, and gaps in her teeth. She appears to have a wide jaw/strong chin. At the time she went missing, she was 5'4", and variously described as 95-120 lbs.
View attachment 166373
Age progressions:
Eric Glenn Owens
Eric Glenn Owens – The Charley Project
Missing Person Case
Martha Wes Dunn – The Charley Project
The Doe Network: Case File 286DFTX
Missing Person Case
(This is a video that Martha's sister made reaching out to Martha, moreso than providing info about the case)