Rare version of the Stanley 12-004 smoothing plane?

I recently ran into a Stanley 12-004, which is a post-type-20 #4. It is *not* the more common E, F, G , or L that are readily available on eBay, etc. It is post-Cordovan and pre-England. I have found only a tiny bit of info on this iteration, exclusively from this site (it is at the bottom of the post): https://thevalleywoodworker.blogspot.com/2016/07/bobs-illustrated-type-study-of-bailey_22.html

Here are the three photos from the seller along with a photo from the blog above where I highlight two distinct features: https://imgur.com/a/BxjNEUZ

The tabs on either side of the tote and the ribs running from the knob towards the mouth seem to be unique to this model. To the best of my knowledge, they don't appear on any other Stanley-made plane.

It seems to be a potentially rare oddball, which I tend to prize more than most collectors, even if the tool itself is of meh quality. That's the long way of saying I intend to pick it up. Still, I'd like to know more about it. If anybody knows anything, I'd super duper appreciate whatever wisdom you can impart.