In spite of using the advanced search options of Google search, I cannot pin down a single instance of the ironic meaning of “pencil-sharpening” of “unnecessary preparation as a pretext for delaying getting down to work”. So, if someone could come up with such a reference, I would certainly appreciate it.
I saw the term used in this sense in some printed remarks by a novelist (female, and British, as I recall), the relevant novel, which I read, being, I think from the 1930’s.
Following up on ab2’s suggestion that it might be Dorothy Sayers, I googled for “Dorothy Sayers” together with “pencil sharpening” and found a website with a use of the term in the sense that I am seeking:
“Forget all the writerly delays, the websites to check out, the email to answer - how modern technology has expanded the pencil sharpening and paper straightening of yesteryear. But if I want the end of the story, I have to get to work.”