Heya.
On the last point... an actual letter & autograph from DCS has substantial value, while a copy is for information only.
Your call of course; there are some signed things that *I* won't part with, either. ;>
Scribblings and notes you say? There's the vein... need everything described, or pix. Major potential. (Any sketches? prolly not but...)
Lodes of vintage TSR have turned up fairly regularly, most commonly via former employees or friends thereof.
All shrink stuff is very very good, even when it's horrid.
If the container box for all this says TSR (ie from the shipping dept), even
that has value.
F