Lee Oskar diatonic, and custom Spiral tuning, each in 14 keys. Chromatic harps by Hohner and Suzuki.
I built this lap steel to sound like a Pedal Steel Guitar using palm-levers to raise the pitch of two strings. Live video here: https://is.gd/mLius6
This 6-string acoustic guitar became a Hindustani Slide Guitar, a classical instrument of India, with the addition of twelve sympathetic "buzz" strings.
Live video here: https://is.gd/yTC1YA