Certainly Jeremiah. Although it's actually tricky to describe. Wish I could put up a picture or two.
It started out as a standard 15 bar Oscar Schmidt. What I wanted to do was have an instrument that could be as easily played on the lap (but NOT cross-handed) as cradled in your arms (Maybelle style)
I also wanted to cut the tuning time by 3/4 so I installed Schmidt's fine tuning system. Finally I wanted to be able to play any song in any key (while still having at least 3 inches of playing room free around the high strings.)
I removed the two plastic cartridges that hold the bars and cut them down to hold 11 bars instead of 15. I left the base of each cartridge on and drilled a hole in each end. I took the felts off two bars and glued them in the last space of each cartridge. This now keeps the two cartridges stable (like a square) There are now 9 openings left for chord bars.
I placed the cartridges (now just ONE assembly) at the bottom (near the fine tuners) and drilled through the existing holes into the autoharp itself. I then moved the cartridge assembly to the other end (very close to where the high strings are) and once again drilled holes through the existing ones and into the autoharp.
I use thumbscrews with knurled knobs to go into each of the four holes.
I've covered each cartridge with a thin piece of wood (about the size of a popsicle stick) to hold the bars in place. It's quickly removable with one thumbscrew in order to change chords.
Put a tiny drop of glue on the bottom of all the springs, so they won't pop out when tou're changing chord bars.
When I want to play with the harp on my lap (or when I'm working with a student who is very visually oriented) the cartridge is afixed to the left side, giving me about 3 to 4 inches clearance on the right side to play.
When I want to hold it upright I put the cartridge on the other end giving me lots of access to the high strings.
Using simple hardwood, I've cut about 50 blank bars (you could just as easily have used blank ones from Schmidt) and have felted about 35 so far. I played on an album recently where they wanted Jazz chords!! So I felted several bars to play Fm6, Cmaj7, and F#dim.
Sometimes when a student is having real trouble with guitar or banjo, I just insert 2 chords in the autoharp (like D and A7) and have them play it on their lap. We'll do something like Skip to my Lou, and since they have only two buttons to push (and still make glorious music) it can be a real ego boost when they most need it.
I know this sounds terribly complicated but it really isn't. I've done this conversion for several folks now and it takes about two hours. Making a hundred false starts and an equal number of messes before I finally came up with something that really worked has taken about 29 years!
Sheesh, hope that helps.