I've just built some wheels using a DR500 rear hub - the hub shell, brake plate and sprocket carrier all have that 'bird' logo with a three-digit number next to it. I also have the DR400 (and USA-model RS250) sprocket carrier, which fits the same hub shell - it has the 'bird' logo with three-digit number as well. All these parts also have "MADE IN JAPAN" cast in. Curiously, none of these parts have the trademark Suzuki "S", as seen on the brake plate in Pokey's photo. I have a few other Suzuki early PE and RM hub casting parts which I could check, but they aren't within reach at the moment.
I'm happy to be corrected by someone who knows, but I'd guess the 'bird' logo to belong to a company that made dies and/or castings for the Japanese motorcycle industry. Momus' comment about finding the same logo on old Honda parts seems to show that at least two of the 'Big Four' used this company for making dies and/or castings. This obviously doesn't help Short Stuff, as all we know at the moment is that the parts are Japanese! It may be worth posting a photo of the whole hub with some dimensions, in the hope that someone will recognise it.
Regards,
James