Anyone know anything about these old pencils?

[erhunter71]

Some old Yomiuri Giants’ branded pencils. Thought they might be Pentels, but not sure. There are two different clip logo designs and “GIANTS” is etched in the side of the clips. I appreciate any light you could shed on these pencils. Thanks so much! -Erskine

[Alan]

Wow, this must be the first time I have ever seen Cooper Black in relief on a mechanical pencil!

[DarkwingDuck]

It’s the Platinum “P” im pretty sure

I’ve seen them many times without the fancy clip.

[Gunther]

Cooper Black!

[drifand]

Unknown GIANT MP, thy name is PLATINUM MP-200…

… all thanks to the 1977 catalog scans shared by @Linus2K.

[erhunter71]

Thanks so much, @DarkwingDuck and @drifand! Much appreciated!