Re Autoharp restringing: There are a number of ways to replace the strings. If replacing a full set, I usually remove the chord bars and springs for ease of access. extreme care must be taken so as not to loose any parts or get the chord bars incorrectly placed or turned end for end in replacement. This method does, however allow you to clean and inspect both the harp and the bars for excessive wear and damage. Tuning pins should be checked and backed out suficiently to allow for mulitiple tunings without bottoming out.
Probably a safer way for the less knowledgeable is to thread each string up under the chord bars individually without removing any parts.