Shelter 501 or Hana ML?

I know this doesn’t answer ur question - but I also have a shelter. It was retired by expert stylus in the uk and it is better than ever before

I have owned and used both, in fact I am using the ML now. The Shelter was used on a Graham tonearm which was a perfect match for it. It did everything well in my system without being bright or analytical. Very good resolution with a touch of warmth that I enjoyed, especially on vocals. The Hana is installed on a TriPlaner arm and while a good match, not as well-matched as the Shelter on the Graham. 
The Hana ML is very similar to the Shelter, maybe a bit less warm and a bit more detailed, but not much. With a bit of tube rolling you can get similar results to swapping these carts. I had the Shelter for many years, the suspension gave out and I had it rebuilt by Soundsmith which changed it completely. I don't recommend that. My advice is buy the Hana ML and trade it in when Hana comes out with their next top of the line!