I found this guitar listed on Craigslist (Seattle-Tacoma) in November 2015 with an asking price of $3,600. This DA seems to be in really nice condition and comes with it's original RT pickup. Case is not an OEM Ess & Ess case, but still seems kind of vintage and might in fact be original to the guitar.
"1969 AMPEG Dan Armstrong Lucite Guitar with original case and Rock Treble pickup. Not interested in trades, please include a phone number to receive a response."
"No cracks at the jack or on the pickguard. Also no extra pickups, etc. Serial number is A663D, pots and switches are all working. I've had the guitar since 1983, second owner."