Hello Richard,
I have stayed for several weeks in a very nice homestay, at the heart of Patan.
It is located just behind Swotha Square, in a hidden and quiet inner courtyard. There is no signboards, no advertisment, you need to know it to find it. It is called Goathchen Guest House, and it is run by a sweet family, Bijendra and Suhag. They're very caring and welcoming and can let you do your food or cook for you.
They have only two or three rooms in a renovated newari style building. Rooms are very big (<30m2), with bathroom and nicely furbished. There is also a courtyard into the house where you can read, chill or take breakfast. They usually charge around 30/35 $ a night but if you stay long they can probably charge a litlle less.
It is a sweet place full of good vibrations !
Here is the contact : Bijendra 9851015696
Have a nice day !
Isis