Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download -- including a lot of info on fixing and improving the 1920.
That replacement carb from Daytona is an import from Argentina. It has its origins in an ancient local-production licence from Holley to an Argentinian company for the early Valiants in that country. Needs a manual choke, needs linkage adaptation, and it's pretty stone-age with none of the advances and improvements made over the 1920s lifespan though it does have a separate cast iron throttle body. It's a shame the maker (Caresa, website here) didn't pick up and run with the later and better local Holley 1922, but they didn't.
I do wonder what kind of float (brass...?) might be in that Argentinian carb and whether it might be a go in a US 1920 carb. For the record, I never experienced difficulties using the 7.5g and 12.5g 1920 floats interchangeably as long as the correct float spring was used, too.
Overall I like the Carter BBS, which was factory equipment (production option with the 1920 Holley) on Slant-6s '60 through '71 on cars, through '74 on domestic trucks, later than that on export trucks, quite a lot better than the 1920. But these days questions of which is the superior carb design are usually outweighed by what carb you can find that's in good condition.