I'm referring to the "3rd" metal piece of a Neumann EA87. The part you turn to screw the U87 into the EA87 shockmount. When you pull the inner gasket out of the mount with tweezers, its the piece that falls in your hand.

¹ Does anyone here know where I can find a union sleeve nut to attach a U87 to the EA87?
Sennheiser/Neumann Part#: 576547
[Pretty certain 576548 is also the same nut]
² If not, do you know where I can get a piece with the grips that attaches to the gear-like bottom of the EA87 union sleeve nut that Sennheiser is currently selling, assuming such a thing exists?
³ If anyone has a Neumann "union sleeve nut" for the EA87 to U87 connection, that you're not using, do you wanna sell it?

Here's the details..
I got a 90s EA87 for my late-70s U87 from a fellow "slut" online. I believe the previous owner was using it for a TLM103. Unfortunately, that was only possible because it appears to have an EA1 nut, or something like that, rather than the normal EA87 union sleeve nut. In fairness, I should stress that the previous owner seems to be being very accommodating to correct the issue. However, we're having difficulty finding the correct nut... thats why I'm reaching out to y'all.

I found a company in Europe with the "EA87 union sleeve nut" that I need. Pics in their online store look like the original nut an EA87 would normally come with (Part#576547). Pretty sure its old stock.
Unfortunately, that online instrument-parts store said they're not doing international trade right now and suggested I go to Sennheiser. That's a problem. Although Sennheiser has the correct part with the same part number as the new "old stock" that I found for sale in Europe, the part Sennheiser has looks functionally correct but visually unappealing. It appears they've changed the design.
It has this gear-like look where your fingers turn the nut to screw the U87 into the mount, rather than the normal grippy cylinder, like its incomplete and supposed to have a separate piece that covers it. I assume they changed the design to cut down on material and that there's a prettier plastic piece that covers the "gear" with grips for you to turn it but, so far, I haven't been able to find such a piece for sale on their site.

The pictures:
As you'll notice when you compare the grips of each...
¹ What I need (Right part)
² What I have (Right part but for wrong mic)
³ What Sennheiser is selling ("right" but looks wrong)

Have you tried something like this?

https://www.ebay.com/itm/Silver-Micr...MAAOSwCoBajjCx

It doesn't have a groove for the rubber piece to hold it in, but if you are not planning to take the mic in and out of the mount it may not matter.

I have a non-shock mount for my 1976 U87 that the ring has broken, so that nut is intact. Wasn't really planning on selling it, but if the other one doesn't work, contact me and we can talk.

I probably will be taking it off the stand and putting it away each night.
I left my NT1A on the mount and had some stuff happen that kept me from getting back in the studio for a couple months an, by the time I finally got back, the humidity had made the mic non-operational. I think I'd lose my mind if that happened to my U87.