ISO 18 gauge shotgun shells

[CAVSCOUT]

I recently acquired an antique sxs in 18 gauge.
Where in the devil can I find the shells. Expended hulls that I can reload would also work. Any idea on values of the shotgun as well? I can’t find anything in regards to the maker. Thanks

 

[savannahboy]

Beautiful old French shotgun, but I would not shoot it. Top lever position shows it to be well worn.