How to find correct crown for UG Polerouter 204610-2

Hi all,

Kindly seeking some input from the seasoned UG experts on the forum.

Just last weekend, the crown on my Polerouter came undone and got lost. After spending hours on my hands and knees in my apartment and praying for the crown fairy to bring it back, I've lost hope and decided to shift my focus on finding a replacement— which I realize might be near impossible.

My Polerouter Date is ref 204610-2, 34mm size, with a 215-2 movement. The case tube is 2mm. My watchmaker had a look and told me there needs to be a gasket inside the crown.

I've looked on eBay and there's nothing even close to a perfect match. This is the only one I can find that even comes close, although I think it may look large on my watch:

https://www.ebay.com/itm/266218982500



Any help confirming what the correct crown for this reference is, and where I may be able to source one would be hugely appreciated.

Here are some photos of the crown of the crown before it came undone, the tube as it protrudes today, and the watch just a few days ago in all its glory, for reference.