I am truly fascinated with T206 sheet layouts. I'll never know the exact composition of a sheet or even the number of cards, but there are absolutely hidden clues to the set out there. Little pieces... little pieces that when put together start to reveal something.
I recently picked up this Herbie Moran ghost (thanks Adam). Based on the scans, I was pretty sure I could make out Herbie's (left) neighbor. Once I had the card in hand, I was able to match it up with Fred Mitchell:

I think that's really cool. But that's not it. This Herbie Moran is a Piedmont 350...
there's another really interesting Herbie Moran Piedmont 350. A Moran two-namer with Frank Arellanes on top:
So, assuming that the sheet layouts for these guys didn't change during the Piedmont 350 run (which may be a leap), we now have three known neighbors: