As long as it is a mineral 2T and not synthetic the brand is immaterial.
As prev posted I use Penrite Greenkeepers 2T which I get from Supercrap whenever it is on special.
Gulf, Castrol, Penrite, Homebrand, Dr Spocks Medicinal Rubbing Oil and Paint Remover... doesn't matter.
All you are doing is putting back in the 'minerals' that the low sulphur fuels of the last 30 years don't supply to the olden times fuel systems of yesteryear.
Indeed if you are using aftermarket/modern injectors and fuel pumps on an old mill then 2T does absolutely sweet FA