https://pianoforum.net/smf/index.php/topic,5273.0.html
Thanks, Steinwayguy.

Have a look here also for Beethoven sonatas.
https://pianoforum.net/smf/index.php/topic,2748.msg23723.html#msg23723(progressive difficulty list for all 32 sonatas)
What about Haydn? I actually like his sonatas better than Mozart’s. Have a look here for some discussion on them:
https://pianoforum.net/smf/index.php/topic,4046.msg36920.html#msg36920(grades for all of Haydn’s sonatas)
https://pianoforum.net/smf/index.php/topic,3729.msg33455.html#msg33455(Haydn sonatas – best recordings).
Finally, out of the well beaten path here are some interesting sonatas more or less of the same style (they are all from the Classical period):
C. P. E. Bach pretty much invented the classical sonata (and sonata form) and was a huge influence on Mozart. Almost forgotten these days and almost never played, his sonatas are real gems. Again, all of the sonatas are around grade 7-8, so you should be able to manage. I particularly like w62 in G.
Two obscure composers, Christian Latrobe (3 sonatas op. 3) and Fanciszek Lessel (3 sonatas op. 2) are also around grade 5/6 and the style is similar to Haydn.
Then there are the Clementi sonatas – not the sonatinas - (if you play K332, then these will all be doable – just pick your favourite) which are all very good.
Finally – and starting to enter the romantic territory – you could try the almost unknown John Field sonatas op. 1 (my favourite is Op. 1 no. 1 in Eb).
This should keep you busy.

Best wishes,
Bernhard.