As far as I understand, the SP-10 only came with steel nose cones.
The SP-10 had a different metal nose cone from the SP-15.
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The Piston series is one of those features that just seems to fall on the side of ‘novelty’ rather than ‘innovation’. Coz, it really isn’t that much harder to hold on the button and slip the lead back inside.
It is so cool to see a full set like yours all laid out 
For myself, I kinda stopped after I’d gotten the SP-15 pen and pencil set, mostly because I’d been so cheesed off by the cracking in my brown SP-5. Never really had a malfunction though…
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Thank you for the details! I made a mistake in my thinking and equated “opaque” with “plastic”, and according to your picture the nose cone of my SP-10 is the original one.
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Found this today: The Uni Return’s seems to function like the Ohto Piston
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Interesting. At first I thought the nose cone was unscrewed, but it looks like they removed the rubber grip in order to make the mechanism more visible.
Dave (@Kiwi-d) posted about this pencil back in 2007 on his website: HERE
lakshim-918 on eBay (Japan seller) has this listed–exact same photos as from the Mercari listing. Another example of THIS
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lol - I had seen a post on the MP subreddit where @drifand had mentioned this and a Koren model that was similar in function. I have a proxy open and happened to stumble across it by accident so after a quick look elsewhere for comparison pricing, I pulled the trigger.
Then I stared researching it a little more and ran across the @Kiwi-d post and had instant-regrets because of the grip. -
fingers crossed its not a gooey mess 
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Fingers crossed for you @Pdunc67 but my grip melted into sludge many years ago. I’ve actually still got the pencil, and keep thinking about getting a 3D Printer person to make a grip.
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Might work?
Saw another video where they used gasoline 
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We are way past just removing a sticky surface layer. I’m talking actual oozing liquid and the whole grip permanently deforming under light pressure.
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@Kiwi-d Your comment about having someone 3D print a pencil part got me thinking about you in the context of design. I know you kept your top 10 list going for a long time. I am curious what pencils don’t exist but would beat out the others on your list if someone would only make them. Have you put together some designs of your own?
Good question. I did once think of MechFrankenPencil but I haven’t really ever given much thought to designing some pencils myself. I’ve been greatly reducing my collection over the past few years so at some stage I guess I have to think about my Top Ten Keepers. I don’t think its going to look anything like what I might have expected five years ago.
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Would love a top 10 update some time.
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Yes, it’ll work. Nail polish remover works too, as I think it has a kind of acetone like solvent in it. And you can pick up some of that stuff real cheap at the dollar store.
With some of them, alcohol swatches work (those individually sealed squares you typically see used by medical professionals for giving shots). In fact, I’ll always start with that. Sometimes if it doesn’t remove much, it at least weakens the residue a bit such that when followed up with something more aggressive, it’s easier to get the surface clean.
Most of the time the result is a glossy hard plastic left behind. If you really want it matte, you can follow up with micromesh of a sufficiently coarse grade.
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