This is the only one I can find, you flash it like a custom ROM and would then just have to update as normal after its setup, this will return you to a very early stock rom.
FIRST MAKE SURE CID AND MID MATCH..........
http://www.htc1guru.com/dld/guru_reset_m7_2-24-771-3-zip/
will this allow me to update over the air update to sense 6 and other future updates