It sounds like you want to make it have fewer chords, but a richer sound. Did I get that right? Great idea!

It can be done. You will have to do some arithmetic. Figure out what key(s) you want. There are some key combinations that work better than others. You will have to make new chord bars. Figure out what strings you want doubles of. Then you will have to cut some felt or some material for each new chord bar. Some folks use old mouse pads for the material. Or plain old felt.

Then glue the pads on each chord bar in the right places to make the enhanced chords. I don't have the "formula." But I know it can be done; it HAS been done. I *think* Bryan Bowers has done some of that sort of thing. When I have seen him perform, he brings one of those tall rolling pastry things with trays that hold different harps with different setups.

Bev and Jerry used to be the Mudcat resident autoharp experts. Maybe they could weigh in? (Did one of them or both pass away?) Also, BillD may have some intelligence.

Try here: https://autoharp.org/

I will try to dig up my notes on the subject. One thing to think about is that if you're going to all this trouble, you might want to make sure the harp has a sound that you think is worth the effort.

AND...report back, please and let us know how it went.

Saul