I think this is his wife, Jody:
http://www.mylivingnutrition.com/about/ so you might try her to get his whereabouts - otherwise, nothing new about him. You can contact her at the email provided on the Contact page or the envelope at the page bottom. Here's her Linked In -https://www.linkedin.com/in/jody-engstrom-879973105 Here's her FB -
https://www.facebook.com/jody.engstrom.33 Here's her IG -
https://www.instagram.com/mylivingnutrition/
This guy's posted multiple videos of him and so may know him:
http://www.danielrobertsstringworks.com/
Looks like he let his domain name expire last year:
http://digituna.com/website/engstromguitars.com
Otherwise, good luck!