My low tech solution is to Add a Note under each listing saying dotCA 7/16 or dotCOM 7/16.
Only the seller sees those notes.
This also tells me when a listing is getting stale.
Oh! SEEN!
Like by customers?
As long as you have a shipping cost for a location, customers in that location can see the listing.
To cross check that, go to the site you are worried about, check in as a Guest (not as a member) and enter your listing number.
Or just look to see if there is a fee on the Shipping tab.