I have a few Beach boxes, some branded Beach, others Mastercraft. The construction is identical everywhere except the branding, and sometimes the louvers next to the badge. I have a Mastercraft box almost identical to yours and it has no badge or louvers. I have another Mastercraft-badged Beach and it has the shield-shape badge just like Beach, except it says Mastercraft. Then two others with normal Beach badges.
Point is, it's absolutely a Beach, even if it doesn't have the normal shield-shape badge. Beach made these for a lot of different brands. I've seen them labeled as Mastercraft, Gray, Craftsman (though they usually have black drawers), Mecanika, I think AC Delco even? Something like that anyway.
You've got a great box anyway. Spend an evening in the garage with some mild degreasers, a scrubbing brush, and some polish, and you'll have a nice box with a great history.