Non-Denominated 39c Liberty/Flag - Scott 3972 Or 3974 ?

I am trying to identify a SA booklet version of the non-denominated 39c Liberty/Flag stamp. It is dated 2006, does not have microprinting, & is die cut 11 1/4 x 10 3/4, so I believe that it is either 3972 or 3974. Any help greatly appreciated.

For perf 11.25x10.75 & a non-denominated stamp, I see 3 choices. 3966, 3972 & 3974. 3966 was issued in a self-adhesive pane of 20. 3972 was issued in CB20 format while 3974 was issued as a VMB (Vending Machine Booklet). Consequently, 3974 should appear in panes of 4 or 6. 3972 is in a double-sided booklet. 3966 should have plate # P1111 while 3972 should have V1111. The 3974 booklet had no plate #.
Added: I had assumed you were identifying a full booklet. It now dawns on me that this might not be the case. For individual stamps, look at the extreme lower left corner. On 3972, the blue sky extends beyond the 6 in 2006. On 3974, the 6 extends beyond the blue sky. On a final note, 3966 appears similar to 3972 but, being from a pane, will have die-cuts on all 4 sides rather than 2 or 3.

Yes, I am working with a single stamp, and the sky does extend beyond the 6 in the date. So I have 3972. Thanks

Just realized that I overlooked the fact that 3966 was issued both in pane & CB20 format. But 3966 has microprinted USPS on the top red stripe. Since your stamp does not have microprinting, it is, as you have ascertained, 3272.
Just noticed my typo ... should read 3972.

A while ago, I purchased a bulk lot of U.S. definitives. There were alot of 39c Flag & Statue of Liberty stamps. I put together this sorting chart to speed up the process of searching out the varieties.





I hope somebody can make use of it. It helped me tremendously.

Robert

My stamp has the white shadow effect, which is further confirmation that I have 3972. Thanks guys for all your help.

Excellent identification chart! Nicely done. Thank you for sharing.