Scanned below is a block in my collection. I was looking up this exact stamp in the 2022 Scott Catalogue Volume 2B.
I could not find it.
Czechoslovakia Scott #254B has now been deleted from the Scott Catalogue, see page 970.
However, I did find it on page 166, Scott 2022 Volume 2A, under the "new" old country of Carpatho-Ukraine, which I had never heard of before.
Carpatho-Ukraine Scott #1, mint $4.00, used $40.00
The 2022 value for a mint copy dropped in half from the 2019 Scott value for the same stamp, different "country."
I will have to print out a new label for my block, but heck, it is a #1 now.
For all of you collecting #1s of the world, or a stamp from every "country," this information is for you.