Jeff Kunkel asked,

> Are there articles anywhere on how to build vox humana organ pipes?

Hi Jeff, this classic book will help you to get started:

Organ building for amateurs : a practical guide for home-workers.
Containing specifications, designs, and full instructions for
making every portion of the instrument.
By Mark Wicks. [ July, 1887. ]
Illustrated with over two hundred illustrations and explanatory
diagrams. This book is an unabridged republication of the original
and is available from the ORGAN LITERATURE FOUNDATION, Braintree,
Mass. 02184. Price $15.00 postpaid.

https://archive.org/details/organbuildingfor00wick/page/2/mode/2up 
Organ-Building For Amateurs
https://ia600303.us.archive.org/25/items/organbuildingfor00wick/organbuildingfor00wick.pdf 

Best regards,
Robbie Rhodes, MMDigest