Vintage Feather Artist razors?

Hi, I know this is sort of a subtopic, so correct me if there's a better place to post this. I recently found two old looking Feather disposable blade razors at a yard sale. Both have a sort of plastic slider on the back of the blade, unlike new Feather straights. One looks much older and has a hand-engraved serial number. I order a box of blades and these do take the same blades as modern Feather Artist razors. Does anyone know anything about these? I've found nothing on the web. Pics soon. Thanks.

Btw, the newer looking one needs some repair. The older looking one shaves beautifully.

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Here's a pic