I can't find any. Nary a single one.
This is disappointing as, no doubt you're aware, there's a great demand for his prints and also for those of his wife Elsie. Despite my affiliate membership of several online print retailers there seems to be none to be had.
But they'll be along one day.
Meanwhile, there's a link to an exhibition of his work here. As always, the web isn't the best way to interface with a painting, I think you have to stand up close and kind of lean into the picture to get a real idea of how much detail is in it. You stand away, you see the picture. You stand close, you see the man.
But some of these presented graphics blow up quite well so it isn't too bad.