I couldn't find the A.P. Curtis try gun patent, but he designed try guns for Hunter Arms, Lefever and Ithaca

Westley Richards
https://www.theexplora.com/the-westley-richards-try-guns-for-shotgun-measurements/

Of interest
https://www.youtube.com/watch?v=dVCsoO5Ncvg

H&H try gun
https://www.youtube.com/watch?v=Y7ZMeiKkp-Y

Perazzi at about 4 min.
https://www.youtube.com/watch?v=TkdRji7BTo0