Numismatic Research Dead End

My coins are generally not significant enough to carry around a provenance but I still enjoy digging to see if I can find additional information.
This is the coin I recently picked up. Looks like it mentions the Halbert Carmichael Collection which was sold by Noonans in 2014. Here:
https://www.noonans.co.uk/auctions/archive/special-collections/318/247859/?keywords=1693&x=0&y=0
Both mention a purchase in Seaby 1981.
https://archive.org/search?query=seaby+1981
I reviewed all the catalogues here but no matches to my piece in the listings. So then I checked 1980, 1979, 1978 onto 1970 before I gave up. I suspect this is where the trail goes cold and this somehow just evaded the monthly circular? Perhaps something offered direct.
Just thought I would reach out here to ask if there's any resources I can check I may be missing.
Any help would be appreciated!
https://numismaticmuse.com/ My Web Gallery
The best collecting goals lie right on the border between the possible and the impossible. - Andy Lustig, "MrEureka"
Comments
I doubt that this will help, but Spink acquired Seaby in 1996. Maybe in their database which is very frustrating at times.
If you couldn’t find it in the old Seaby catalogs, it’s always possible Seaby bought it from another auction in 81 and did a quick flip. I can check my auction catalogs this weekend from that time period.
Have you tried the British coin forums?
Doggedly collecting coins of the Central American Republic.
Visit the Society of US Pattern Collectors at USPatterns.com.
Predecimal.com ? I haven't if that's what you mean. Not sure I've looked there much at all. Are they active?
https://numismaticmuse.com/ My Web Gallery
The best collecting goals lie right on the border between the possible and the impossible. - Andy Lustig, "MrEureka"