I don’t have what you need.  You are probably watching eBay already.  In the interim, you may want to see if one of the modern manufacturers can help you out.  Twenty years ago I would have suggested Axtell, but they have gone out of business.  Montana Vintage Arms may be able to help you out.  They make a non-windage #133 tang sight that has a similar looking backslide assembly and eyepiece to an original.

https://montanavintagearms.com/product/133-vernier-tang-sight/

Here is an original graduated peep sight from my collection that shows some details.  

I see on the underside shot of your sight there are numerals on the spring.  That should tell what model it fits.  If it says 76 it then the leaf will align at 90 degrees to the bore for that model only.  Any other markings will fit all the other appropriate models.   I hope that makes sense.  I learned this information here on WACA forums.

Best of luck with your search.

[email protected] said
It’s marked 73.  Hoping to find original parts… have a good inventory of vintage sights & other related items to trade.  I know people can be reluctant to let go of old stuff for just cash since they ain’t makin’ old stuff anymore.  🙂 

  

Problem finding small, unmarked, parts such as this slide, is that the person who might have inherited it in their dad’s parts box has no idea what it is.  Thus you can often see ebay listings like “unknown gun part,” or “miscellaneous gun parts.”  The A5 screwdriver that Steve Norton recently inquired about is a prime example.  I said (in order to avoid a long drawn out reply) that the one in Campbell’s book was the only one I’d ever seen, but actually I did see one on ebay, mixed up unfortunately with about two doz modern open sights & other misc parts like springs, etc, the whole pile of junk priced about $300.  Offered the seller $50 for the part, but he refused. Since this junk pile wasn’t remotely worth $300, nobody bought it, so it was re-listed.  Raised my offer to $75, again declined.  Re-listed yet again, same story.  I expected seller to come back with a counter offer, & would have paid $100 or more, but this fool was determined to sell “all or none.”  It NEVER sold, at least on ebay.  And if it was sold elsewhere, maybe at a gun show, I’d wager the buyer had no idea what the A5 tool was!

I have the same ’73 marked sight in the short-staff version.  I presume the long-staff is worth more, so I’d sell you mine, if you want to rob Peter to pay Paul.  But then you be left with another unusable sight.  This problem would have been prevented if the disk had been been made non-removable by flaring out the end of the aperture after it was installed.