Are These 423B Washington Stamps?

I am not a collector, but had some old stamps that I'd torn off some envelopes as a kid back in the 70's. Was going through some old things and found them in a box after 40 years and looked them up. I was looking through the Scott catalog and potentially identified them as 423B 10x12 stamps or perhaps 499's; I also had two 554 or 634 10x12 stamps; and four 423 A or D 10x12 stamps. I have ZERO experience with stamps, with no way to measure the perforations. I almost threw them away this morning, but figured Id wait to see if anyone is willing to chime in on these? Just want to make sure these are common and not rare.

Short answer: No.

Longer answer: Perforations are *gauged* at the rate per 2 cm, you appear to be counting them instead, which will give you an incorrect result. As an example, the left two stamps are both perf 11, on all 4 sides. They both have a certain "cast" to them which indicates they are among the offset-printed stamps of Scott 526 to 528B.
The Stampsmarter.com website should help you through the ID process.

Hideo Stevearino.
A good guess would be NOT 423 anything.
Why?
Because of the post mark 1921.
Who held onto stamps for 7 years before using them?
Not too many people.
Could be 525.