I would 2nd (or N-nd) the idea to upgrade phono stage first. I think both the Pro-Ject and the Vincent (a SS stage with a tube buffer) seem like they’re not quite up to the level of your Hana ML. But upgrading the phono stage first would allow you to enjoy significant benefits immediately without even having to re-mount and adjust the Hana all over again.
Good tube phono stages (a real one, not just a tube-buffer built in) show up on the used market often, and they’re a HELL of a lot easier to ship safely than a turntable.
As for Classic-to-Concept I’m not sure that would be just a "lateral move" (I’ll take a Concept over Classic any day), though you should avoid the Clearaudio magnetic bearing arms (go for Satisfy or Tracer at least), and ideally I think you should strive for a bigger upgrade step like the Performance DC in that line.