It would be tough to fake that broken/misaligned 'e' key.
That is a wonky signature, but something tells me a forger would write a date under the signature, since most manuscripts are dated. But Bukowski didn't start dating the manuscript until 1971.
Plus it's Scott Harrison. He's a nut, but I would trust him on any Bukowski item.
He's asking a premium price for that combo though, and I don't think it's justified. Especially since Martin trimmed the manuscript to make it fit into the book, which makes it less valuable. As a manuscript, anyway.