Posted By:
Scot ReaderDeric,
The Factory 42 overprint is rather common; some might pay a small premium but I would not. The Factory 649 overprint is somewhat more difficult and generally carries a small premium--perhaps 20%-30% over a common back. Only 35 subjects are known with the Factory 649 overprint which contributes to its scarcity.
I doubt you have an authentic Wheat with Piedmont 150, if that is what you meant to convey. Wheat is only possible in the 460 series.
Scot