Johhny, you've got me thinking- what is the most valuable T206 scrap card? I came up with the following:
1- Wagner scrap
2- White (Albino) Plank
3- Light Blue Plank missing color
4- Leon's massively overstruck Dom Mullaney
5- Jeff Lichtman's split-level Cobb Green
And if we expand the definition of scrap to include proof cards, then the Wagner proof strip and the Eddie Collins proof would also be at the top of the list.
But the value of most of these cards comes more from the player- Wagner, Plank, Cobb- than from the fact that they're scrap. The exception is the Mullaney, whose value is derived solely from it's being scrap. So I guess Leon's card is the leading scrap card in the set. IMHO.