Cipex 1947 Cover (948)

I have been having a great time going through my Grandfather's collection which I inherited several months ago, researching the various items in his collection, but this one has me stumped.

I have easily found more than a dozen covers for this CIPEX souvenir release commemorating 100 years of US postage stamps and some of them are close to what I now have in my possession, but I cannot find this specific cover anywhere online. Here is a close-up view:

At the lower left corner it appears to be signed "DAY LOWRY"


Any idea who produced this cover? Is it particularly rare? Any information that can be shared would be gratefully appreciated!

Thanks.

The cachet artist was Day Lowry.

There was another thread with a little bit of information about him:
https://goscf.com/t/43151

Joe

Thanks Joe! I was able to learn that he designed covers for Aristocrats. In fact the cover shown here appears to be a modified version of the Aristocrats cover he did for the 5 cent Benjamin Franklin stamp pictured on the CIPEX souvenir sheet. It looks like he just "slapped" the Washington "X" stamp on that particular cover at an angle to create this cover. But why can't I find other examples of this specific cover on-line? I've spent hours searching! Is it particularly rare? (And if so, is it valuable?)

Although this link will eventually go bad, here is the same cachet which recently sold for $4

https://www.ebay.com/itm/DR-JIM-STA...047675.l2557

James T. McCusker fdc site has them for sale. Type in Cipex and Aristocrat covers.

http://www.jamesmccusker.com/shopping/

Rare or not, it is a nice cover.