Those look like short ribs, cut longitudinally.
Sorry, couldn't think of a better word.
The packer that the stores get is a nice, blocky piece.
I do a lot of Flanken Cut short ribs and my QFC and Safeway guy will show me the packers and they cut what I want.
Flanken is 1/4" thick cross-cut for hot and fast grilling....I have a killer marinade that will change your life.....it's a Gartner's counterfeit.
Here, short ribs are cut into cube-like pieces, but a long cut like yours would be nice. (beautiful job, BTW)
I just did some long beef ribs, which were like a St. Louis cut only beef that I got at Gartner's.
It is hard (impossible) to find meaty beef ribs in the super markets...Gartner's has good beef ribs.
I used Weber Chicago and they came out great.