If anyone is interested there is an authorized biography of Henry Darrow out, Henry Darrow: Lightning in a Bottle.
The author of this book, Jan Pippens, responded to a query at IMDB about DVDs of High Chaparral being available,
Legitimate High Chaparral DVDs have been released from Kinowelt in Germany (all 4 seasons, with option to set language as the original actors' voices in English)and by a company in the Netherlands (1st season). The Kinowelt DVDs can be purchased on Amazon. Kinowelt quality is excellent - I have not seen the Dutch release but am told it is fine quality as well.