Larry wrote:

Scott lists an 1857 Queen Victoria two pence blue stamp, number 21, as type A2
(this is Gibbons type 3), perf 14 on white paper. I do not find this in
Gibbons. Is it hidden there somewhere? If not, why is it not listed? (Maybe
Gibbons 35 with no blue paper visible?)

The only 1857 issue I find is 1857 July 2:
Gibbons #35,
Michel #11 B II.