Postage Paid Cover With Unusual Slogan Cancel

Here is a new cover to my collection, which I bought to secure this particular postage paid cancel.

From Walsh & Butts, NSSC, I believe that this is PP4, a 3 line handstamp in violet used between 1918 and 1919.
It has a faint violet circle cancel, which I have not deciphered yet...

But also, I was surprised to see that it has an odd, possibly very rare, slogan cancel : the "Food" one, but with a "2" in the grid...faint but needs more research.


Just thought I'd share and welcome any comments, observations or clever funny points...

This may be the research you need:

WT1,

That is it, thanks. I really need to read all those back issues.

I think it is clear that the cover is PS1a then.

Also, in the document you attached it also appears to be two varieties of this PS1a--one with a curve in the hub by the date and one without. the sentence is just below the yellow highlights.

I appear to have the one without the curve...and I think I'll research and contact the individual referenced.

Many thanks