Ecuador 1920 - Help

I have these three stamps as part of my collection. I am able to identify the original stamps but not with the overprint. There are other overprints but nothing like these shown. Wondered if anyone out there can help me with the year (ie: were the overprints done later on these 1920 issue stamps?) rarity, value, etc. Thanks in anticipation.

In my view, 1 & 3 are from the 1920 "Oficial", series overprint of the 1920 Guayaquil Independence Centennary issue. The 2 is from the regular series. The plane seems to be a private overprint. Well, that's my view!

Somebody playing around with a rubber stamping kit .

Q/ Does anybody else think that the wings are at an odd angle to the fuselage?

Q/ Does anybody know what that softie ice cream cone is, or what it is doing?

For what it is worth, here are a couple of images from the 1950 Sanabria's Air Post Catalogue. Looks like the overprint is Sanabria's SO3?

Thank you 1840to1940. That information is very helpful. Appreciate your post.

What have we established here .........are those fake overprints of real overprints ? or are they private overprints that got into a catalog by mistake ?------still look like homemade overprints to me .

I'm certainly unclear. I've found one image on the Web for these stamps, and this from an ebay auction for which the original page is inaccessible (and the Googled image is too small to be of any help).

I did find a citation to this interestingly titled article, "Ecuador: 1922 Overprints Are Private, Nothing Semi-official About Them" by Roberto Levi-Castillo (Aero Philatelist Annals) that is in the APS Library and which might be relevant.

I'm uploading a more detailed image of the overprint in question, although since it isn't an image of an actual overprinted stamp, one can't be certain of its accuracy. Now that I stare at the overprint, that is one strange looking airplane.

Well I'm obviously going to have to dig a little deeper here! Will have to go on the back burner for now as other stamps/exhibits are clamouring for attention. Thanks everyone for your input though, it is appreciated. If anyone has further verifiable information, I would still like to hear from you. Interesting to have in my collection if nothing else.