Someone near the end of his career, but who can give close to league average production for a year or, at most, two while the youngsters rotate through the rest of the spots, might solidify things.
I'm no longer sold on the idea of bringing in a legit LT, though. I was all for it this year, when Russell was banged up, but now that we're (presumably) going to start next season at full strength I'd be willing to roll the dice knowing FULL WELL that having a better LT would lower the chances of our QB getting hurt.
The money could be better spent elsewhere since, at least in theory, it could be spent to bring in longer-term players than back-end-of-career LT's.
Not saying it's a terrible idea to bring in a bona fide LT, but it's not where I'd direct my energies. Double down on defense.