Hi.  I have five similar instruments.  One Christmas I was given one,
with a box of replacement strings to fix it.  I got a second one because
I used minor-key tuning on one.  I used to play them, before I got into
the balalaika.

I set mine on a table, and played the 4 chord strings with a thumb
pick, while the other hand picked the melody on the harp strings.
There are usually 3 sets of four chord strings, and 15 to 20 harp
strings.  I liked the sound of bouncing a pencil eraser on the melody
strings to give a sound similar to the gypsy/gipsy/gipsey/ or Magyar
sound (cymbalo, cimbalom, cibolyn, cimbally), similar to the American
hammered dulcimer.  A picture of one is in the 1902 Sears catalog.

Some instruments are called Zither Mandolin Guitar, some are Mandolin
Guitar Harp.  Sometimes it's called a lap-harp.  Very similar, but more
like mechanical music is the American folk auto-harp; pressing keys
undamp certain chords.

One of mine is a "Harmonium", which uses a pick that is imbedded in
a roller that is dragged across the strings, while a set of buttons
selects the notes to be undamped.  Another one calls itself a
"Bell-Harp", which uses buttons to strike the strings with a weighted
hammer which bounces on the string..

I paid average of $100, 15 years ago.

Will Herzog
Rochester NY