First, I like the way you refer to the violinist as "my accompanist". It's usually us pianists who get lumbered with that description! It's worther remembering that Beethoven's sonatas were labelled "For piano and violins", not the reverse. I even read somewhere that an early edition of the Kreuzter Sonata was headed "Sonata for piano, with violin obligato".
Some of the Moart sonatas maight suit, for example the ones around K300.
I particularly love the 2 movement K302, especially the 2nd movement:
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