Why would you assume it needs preserving? Looks to have no active issues to worry about. It will hold up just fine with nothing, but if you want to add Renaissance Wax you can.
I promise it will be just fine, left as is.I just don't want it to deteriorate. I've never dug a button before so I'm not familiar with how they hold up.
First signal. first plug of the year.
You got it for sale on eBay already?
https://www.ebay.com/itm/223987388330?ul_noapp=true