Mis-perforations are a highly collectible item. Depending on how severe the perforation shift is, it could be worth a few hundred dollars. Your best bet would be to consult a dealer in your area. Probably the most could be obtained by having it in a well advertised philatelic auction.
I have sheet of CPA stamps I can sell you.
It's the little row of tiny holes that are between the stamps, making it easier to separate them.
There are links below to a proof sheet of stamps and a picture of a single stamp.
A stamp that has not been used, therefore does not have a stamp from the post office on it (those black squiggly lines)
Presuming the postage is of the correct amount, and the stamp is entirely on the front of the envelope (not 1/3 on the envelope and 2/3 over the top or side) it should not matter.
This is a two-cent stamp, so a sheet of 50 sold for $1. You would find it hard to get more than that for it, unless you chanced upon a collector who especially wants one. These stamp can still be used for postage, but who want to put 21 of them on his letters?
That would be Scott number US 2496. A full sheet of these stamps has a catalog value of $44.10.
The market value of a 1976 half sheet (a type of postage stamp sheet) can vary significantly based on factors such as condition, rarity, and demand among collectors. Typically, a half sheet from that year may range from a few dollars to several hundred dollars. For a precise valuation, it's best to consult a stamp catalog or a professional appraiser.
These came out in 1968, both the coil and sheet type.
HARDING MEMORIAL ISSUE 1923 Denomination: 2c Color: Black Print Method: Rotary Perforation: 11 (horizontal) VALUE: Used $25,000.00
That would be Scott number US 1124. A full sheet of these stamps has a catalog value of $11.00.
According to Whitman Publishing, $0.50 for a single mint condition stamp and $17.00 for a sheet. I checked because I have the same stamps.