When Chris Cavalier sold his collection in 2006 (hard to believe that was already 10 years ago) there was this item listed for sale:

"Photocopy of the manuscript called The Shine in binder from Ziegler Associates, LA. 527 pages." He had it listed for $700.

I always regretted not buying it but I bought so much other stuff from that collection that I had to draw the line somewhere. I agree that the corrections are cool and from the one example you showed I am pretty certain it is King's writing.