441 is not a valuable stamp and it generally looks legit. (Bottom edge is rough, but width is ok.) There is a funny bit on the back which is attached very very flat to the back. I'm guessing paste-up but I haven't come across a paste-up before. Agree?
This is one of the most interesting, more affordable and one of the last Hoe flat plate coils with paste ups before they were replaced with Stickney rotary press coils. The perforations for these Hoe flat plate printed gauge 10 (Kiusalas 79) coils are slightly different than the Stickney rotary press printed gauge 10 (Kiusalas 80) coils.