I keep reviewing the comments people make about Autoharps and where they get them and there seems to be a thread in many of the comments. People go to shops which do not specialize in this instrument. I agree many tops are twisting and are expensive to repair. OS covers these flaws and if you got it from a reputable shop the person should go to bat for you and have this problem fixed or the instrument replaced. They are still covered under a 5 year warrantee.
Cheap is not always the way to go. In my shop( Appalachian Instruments)I use only original factory parts and back this up with service since 1981.
Before you buy an instrument see how much space there is between the strings and the felts. Are the felts deeply grooved? If so they might need some attention. Are the seams cracked and lifting? This could be a sign of improper storage or water damage. Have people substituted guitar strings for autoharp strings. They may not have the right dimensions for the proper pitch.
Good Used instruments are available from around $150.00+
Shop around.
If you need help I am as close as an e-mail ( robertbriehl@yahoo.ca)
Bob Briehl