Yeah, I see other Bandai kits branded as NuclearModels such as the Stormtrooper.
The sprue shots in one of the sites literally show the exact same B1 sprue for the R2 kit.
Whether these are recast copies or actual Bandai made sprues just repacked is unclear, but there is no doubt the source is a Bandai master
I wonder if these might be the equivalent of Revell legally repacking stuff for a market that does not have a Bandai license, or if someone may have access to Bandai wholesale stuff and repacking them to skirt the system