Is This 2c W-F An April Fool's Joke?

I have a couple of questions about the attached item. First, does the cancelled stamp look original to the cover? I understand how the gap in wavy lines can form due to the thickness of the stamp paper, but I'm not familiar enough with this 1915 wave pattern itself to know if it looks right.

Second, what's with the steep increase in valuation of the 2c Washington, Scott #453, between 2006 (earliest Scott catalog I have) and 2019? It went up from $3 or so (as I recall) to over $40.

If the stamp and cover are legit, it was a good Christmas purchase on ebay at $2.

I don't think it is original. I don't see any part of the machine flag's wave that is as straight as the cancel on the stamp is.

It looks perfectly genuine. It is possible that the wavy lines are designed to straighten out at the right end, but I believe more likely, that as the letters feed into the Universal machine from the right edge of the envelope and may take a fraction of a second to get up to the high speed of the rotating canceling head - the slippage causing a slight stretching and flattening in appearance of the wavy lines (NOT a flag) at the far right end of the cancel. Here are three other Universal impressions showing the same features.



Wyostamp, gentle suggestion, you ask about the cover, so please show us the entire cover also.

Sound, very fine examples of Scot 453 used, valued in the Scott 2020 United States Specialized Catalog of Stamps and Covers at $45, are quite scarce. Most sound copies are badly centered and collectors may be lucky to find a fine to very fine example valued at $30 or may have to settle for a fine example valued at $$22.50. Very good examples where the perforations cut into the design sell for $12.50 or less depending on how deeply perforations cut into the design.

Most coils of the period were intended for use in affixing machines that guillotined the perforations to insure separation. Unfortunately, most examples have short or missing perforations on one side and are considered damaged. Mutilated examples off cover sell for very little. On cover examples are scarce and may be worth a few dollars even with mutilated perforations, depending on the use and condition of the cover.

John,

Happy to oblige. Your scans of similar cancels are encouraging, thanks.

Stan

And while I'm at it, here is a second cover that was lotted with the previous one (the pair sold for $4). Cancellation lines unproblematic here. Whether I'll be able to distinguish 444 from 453, as the seller implies, is debatable -- but both are good acquisitions.

Since 444 is flat plate and 453 is rotary, it should not be difficult to compare sizes with some off cover stamps.