Any chance you could share your tips for restoring these in more detail? Your methods and products used? About to buy a couple from eBay and they're going to need some help and I don't have a clue how to restore them.
Main thing is to use a very light lube oil, one friendly to plastics. At most, two or three drops are dripped into the top of the twist mechanism (when eraser is removed). Then gently tap the pencil downward (tip-first) to shake the oil downward. Then twist it in and out fully a few times to disperse the oil. That should be sufficient. Other than that, it's just a matter of cosmetics...sanding and polishing, if that's even needed. Sometimes, graphite dust is visible inside the barrel. Because these pencils are heat welded together, I know of no way to open them up without breaking them. So running a thin bristle brush and swab up the barrel is not an option. It just has to be lived with. Unsightly, but won't affect performance.
After years of 'fighting' with various mechanical pencils, I finally settled on the Uni Kuru Toga. Mostly metal look, made in Japan, and has an inner mechanism that rotates the lead slightly every time the pencil is lifted from the paper. Supposed to keep the lead from developing a sharp point. This works 'okay' for Western writers but was intended for the short strokes of kanji characters, not the western alphabet. They have pencils for Western users, but I liked the look of this one better. Reminds me a bit of the rotring pro 600 I had when I was a kid. Fairly inexpensive for what it is (under $10). Looked it up on Amazon. It's the Roulette model. Might upgrade to the self advancing Dive model if I win the lottery or something, and if they make it with a metal body.
Wow! I can't believe you saw this and actually commented, seeing as this post is so old. Thank you. I appreciate it. Also, seeing as I'm female and never learned anything about sanding, polishing, lunes, etc., could you be more specific? Like the brand name of a suggested lube? And exactly what materials you'd suggest to sand and polish and tips on how to do so? There are several I'm interested in buying from eBay but they desperately need help and I can't afford what they're asking for new, unopened stock.
Any brand of rim polish (from an auto parts store) will polish anything on these pencils. As far as lube, I use Otis Bio CLP. It's gun lube but has a thousand uses. Can be bought in a timy tube that lasts forever. I'd avoid any with visible pitting on the metal parts. It's harmless but it's ugly and can't be polished out completely.
Thanks for replying again. Sorry I’m just responding. Lost this post and too me a while to find it again. Thank you for the help and suggestions. I’ll give it a try. Wish me luck.