Welcome to the forum , Mom2Four .
Your "Potty" (as these items are sometimes named) sure does appear to have a very early factory mark , c1883 .
Nice keeper item .
You can find out some fun facts about the brothers & the company history at "thepotteries.org" , in the event you've not checked the site out .
Value on older &/or fancy Potties can get high-ish , for this 'type' of unit .
Glad yours has survived the outdoor plumbing epoch !