I have published recently an article (in Portuguese) in the Brazilian journal Museologia & Interdisciplinaridade focusing on the organs of Terceira Island, in the Azores archipelago.
The article is titled “The organs of Terceira Island in the first half of the nineteenth century: introductory elements for an organolical cartography” and it proposes a virtual itinerary through the various churches of the Island that house organs, in conditions to be played or not. It also gives attention to the circulation of these instruments. As one may know, after the 1834 (1832 in the Azores) extinction of the religious orders in the Portuguese territories, several organs from monastico-conventual institutions were sold to secular churches. It also traces the path some of the organs took from their primitiva to actual location.
The text is available at Humanities Commons.
Here is an example from the Machado e Cerveira organ from Misericórdia Church in Angra do Heroísmo: