Question from a vintage noob. What exactly is a monster?

[T206Collector]

I put a set of 521 together over 10 years, culminating in a mass exodus of cards from that set in April 2007. The only reason I even glimpsed at the backs of the cards was because I knew other collectors will pay a premium for some. I would always sell those and buy more cards with common backs. I was a front collector exclusively.

Talk about taking on a life of its own, my "MONSTER" is now autographed T206 cards. I have 39 unique poses signed, if you count Mrs. Jane Mathewson and Mrs. Blanche McGraw's signatures on their husbands' cards. A complete "set" of those would be perhaps 60 or so. I've been stuck on 39 for two years, and have few prospects to acquire the others, including the following known examples:

Bresnahan Batting
Cobb Red
Cobb Green
Cobb Bat On
Speaker
Chance Yellow (though I've always doubted this one given Chance's date of death)
Lajoie (Batting)
Clarke (Portrait)
Cicotte
Phillippe
Walsh
Donie Bush (should be more common but isn't for some reason)
Cravath
Lobert (should be more common but isn't for some reason)
Rucker (Throwing)
Wilstse (Portrait)
Zimmerman
Boss Schmidt (Net54 member claims ownership, but never produced scan)
Oscar Stanage (Net54 member claims ownership, but never produced scan)
George Moriarity (Net54 member claims ownership, but never produced scan)

If you've got one of these and are inclined to help me, please send me an email.