Interestingly the notes don't say if they are just props or if they were used in performance. They certainly predate harp guitar and harp ukulele photos I have seen by a fair margin.
Before someone chimes in with how early lutes often came with unfretted drone /sympathetic strings- I got you covered. from the Finnish national museum.
Venice, Florence, Rome, Amsterdam, NY, Oahu (plus volcano day trip to big Island), home (Australia ) next.
From the Florence academy of fine arts
A piano guitar from around 1790 made in New York by Dodds & Claus. The string arrangement of 112223 courses has me intrigued as does the piano action which is either missing or extraordinarily clever. I could not see how the tuners were adjusted.
Those are definitely some unique instruments. Thanks for sharing. Just a thought... The arrangement of courses appears similar to how a piano is strung. The low notes are single strings, middle range has double string courses and triple courses for the higher keys. It could be meant to mimic that.