How did I miss this Proust blog? Because it's a few years old, no doubt, but with Proust, unlike politics or popular culture old is good.
There are some old but good writings about Proust in the following books:
Axel's Castle by Edmund Wilson
Studies in Human Time by Georges Poulet
No idea if they are in print or re-issued. My copies are as old as the hills. Undoubtedly there are more modern takes, but I left literature and entered technology, and therein lies a tale.