There is an email discussion group, hosted by Groups.IO, that is devoted to the subject of Combo Organs (well, the discussion does frequently veer into other related areas, usually other vintage electric, electronic and electro-mechanical keyboard instruments). It only takes a minute or so to sign up, and you'll get emails every day, usually about 5-10 on average. This is the best place to share ideas, ask questions, and learn more than you'd ever thought you could about combo organs. If you sign up, please also familiarize yourself with the Groups.io home page for the group. There you can search the archives of messages, so you can find answers to topics that may have been discussed months ago. There's also a Files and Photos section, where members can post pictures and other stuff- there's even a few sets of schematics and some product brochures. If you don't want to get the emails every day, you can sign up for the daily digest, which is a single email containing all the discussion from the previous day, or you can go for web access only, where you can look at the files, search the archives, and post messages, but you won't get replies via email.
You can sign up by sending an email to firstname.lastname@example.org
You can also sign up by visiting the group website at https://groups.io/g/combo-organ
For those of you who prefer Spanish-only, our friend Carlos, from Argentina, has started a similar discussion group in that language. I only understand a little bit of Spanish (Carlos and I correspond using www.freetranslation.com) so please don't ask me questions about it.
SONIDO HIPNOTICO: (http://ar.groups.yahoo.com/group/sonido-hipnotico) Es un sitio en idioma Español, para aquellos que gustan de los “órganos de combo”. Allí tenemos un lugar para reunirnos, mantener correspondencia, hacer consultas y colocar los datos y las fotos de los órganos de nuestra colección.-