Funny what the eye can do… when I glanced at the sticker and saw the 0.5, the font of the 5 looked exactly like the one used by Pentel. So I just immediately assumed this was another Pentel variant.
How long ago did this rip-off come out, and were the internals any good?
I think the late 80s but I’m not sure. I don’t really know anything about these. I’ve been searching for years for info but been getting airballs.
Good place to ask here (Korea bling enhanced stuff)…
From him: Yesterday I was a bit busy so I couldn’t reply. Also, it is because there was a part that needed to investigate the data for the part you inquired about.
The answer to your question is as follows.
Can confirm. On the leadholder, the clip is in contact with the body, so when you ‘knock’, it scratches immediately. Pretty shitty design choice, if you ask me - something that cosmetically damages itself from the very first use. I’ll post a photo sometime.
I also got one of this ￥2,000 version grey plastic box Pentel Mechanica 0.5mm. The box has a lower case Pentel logo (instead of PENTEL, but still in grey color) which is also assumed to be made in 1971. It’s kinda weird that all its accessories are not uniformly “matched”:
i.e.
One thing I’m concerning about is the paper “medal”. In most of the cases, an early ver Mechanica known as the one with PENTEL logo usually comes with a leather made sheath, and this is not something looks like leather, but real leather, and it is proofed on the medal which has “替芯·本皮シース” printed, which means “Leads and leather sheath”, and typically those with Pentel logo were made of plastic, and on the medal it would say “替芯·シース”, which deleted the word leather. My first time seeing a PENTEL logo sheath but not made of leather. Weird!
EDIT - message from him:
I’ve been searching a lot for mechanical pencils related to Pentel’s EXP line. We are collecting BURBERRY-RENOMA mechanical pencils that collaborated with the Pentel EXP line in the same way. However, we will exclude BURBERRY in relation to this lineup. The reason is the poor finish.
Finding a sealed product - After opening - There is the hassle of having to reseal it - But because you are curious - To answer your questions about it - I will have no choice but to provide you with photos.
The PENTEL MECHANICA 0.5-￥2,000 I am sending you is a product corresponding to the 3rd generation. You should have 11 fittings that fit the era exactly.
Can you imagine…
Getting a sealed pencil that comes in a case. You hold onto it for some years. Then one day, you’re feeling like it’s time. You take out a very sharp knife and make sure you break the seal in a way where you can fix it back. You look inside and then see… this:
He is also downsizing his collection a bit and aiding other Korean collectors on getting started and finding high end vintage pencils.
Ask if he is willing to sell some of his pencils to Brazil and help a humble collector 
I actually did just that few days ago, he said he isnt sending anything international out of convenience but wanted to send me a gift, I will post it when it arrives.
It arrived! It’s insane!
I was left a bit breathless when I opened the package.
To the Pentel experts here, correct me if I’m wrong, but these are first gen MEC and PMG, correct? Amazing. Simply lovely.
And the MARS-770… It’s such an amazing piece of history! The paper is the guarantee of the pencil, STAEDTLER says they will replace any malfunctioning MARS-770, on the backside are the instructions.
All items came very very carefully packaged, the pencils came separately in a rotring gift box (I suppose the original contents were a RR600 BP, MP, FP). All pencils are working and over the next days I will use them and write a review for the MARS-770.
I don’t know how to tell whether a Mechanica is a first or second-run. Everybody references the “JIS mark,” but I thought that was only found on price stickers or engraved on the grip (which is not visible here).
One thing that does stand out to me is the presence of “PENTEL” in all caps on the grip; that certainly signifies ancient Pentel status.
Nice! Congrats, Stu. The Mechanica is quite a special breed of pencil.
Yes, the “PENTEL” in serif font is from the earlier production release, but unfortunately your clip doesn’t have “PENTEL” on it as well. So it’s not the first. But still, it’s a great thing to have. Hopefully your sleeve moves smoothly with a nice little bit of tension at the end of retraction (almost a detent). Seeing how the sleeve nestles into place and looks like it’s part of the fixed design is just a thing of beauty. And then extending… you start… and that cylindrical sheath arises… like titan of strength to protect that fragile tip. 
The sleeve is working exactly like that! Very smooth and just a small tension at the end. I’m amazed at the Mechanica, and specially that mechanism. It will make for a great fidget during exams.
You can hypnotize your fellow classmates by consistently but smoothly extending the sheath up and down, up and down, up and down… while you’re reading the exam details and getting ahead. 
Devious! Pulling out the MEC midway through the exam just to get them mesmerized by it’s beauty.
Oh and more than just the beauty. You know that hypnotist trick of the pendulum swinging watch? The idea is to simulate the same sort of back and forth with the MEC sleeve.
No. You have what appears to be a 1st gen MEC, but a later PMG.
All of the 1st gen PMGs I have seen just have the size in italics, but do not say PMG. A sure fire test is to unscrew the back end of the pencil and see what color threads you are screwing on to. If it is black, it is 1st gen.
I have a side-by-side breakdown of a 1st and later gen on the PMG page in the Pentel Book.
