"Vent had been cleared out just a month ago and had been blown out."
"K Frame - I have never taken off the back panel to access the insides. The closest I came to that was when my brother replaced those little Teflon tabs on the rim of the drum many years ago. And I haven't done that since."
OK, I just re-read your initial message, and really, it's a supposition that the vent was completely blown free. Without being able to visually inspect it, you're not sure.
But, say that it was fully cleared, there are still two possibilities on the table...
One, the motor is going, or two, the internals are clogged with accumulated lint that is causing it to overheat. It can be pretty frightening what can build up inside the internal workings of a dryer.
And, when I say taking it apart, I don't just mean pulling the back panel off. You can get partial access that way. When I deep clean mine, the top, front, AND back come off.
That allows me to inspect the rollers and the belt and make replacement plans. Pulling the front also allows me to get into the internal passages that are part of the door assembly to get them fully cleaned out of the lint that accumulates in there.
In fact, I've not done my dryer since I blew my knee out 2 years ago. I need to get that done.
So, realistically, you nothing to loose, but potentially everything to gain, by pulling the cabinet apart and giving everything a good inspection and cleaning.
You might find that everything is perfect. No lint build up. If that's the case, then you really need to start making plans for a new dryer just in case the motor is going and it's not an issue that came out of nowhere and doesn't repeat itself.