Very RARE Esterbrook J Double Jewel--with cutouts--SEE PHOTOS--1947.25 For Sale

Ok, so, I am not exactly sure what I have--I got this through an estate--they had it mislabeled for sure (not an 8ball desk pen). Appears to be a J Series double Jewel. What I don't get, can't find anything on, and can't find another example are of J Double Jewels with the cut outs in cap and barrel on this pen. The cutouts aligns, are identical in size and are symmetrically done. Clearly machine made. I don't know if this is a sales men demonstration pen, shop demonstrator or something else completely.
I priced it based on my total lack of knowledge of exactly what it is. You guys are always great about letting me know what I don't. So...here it is.