I guess that Ampeg was in Linden, NJ until 1970. They moved to the Selmer-Magnavox offices in Elkhart, Indiana in 1971. I saw a SVT810 Cab 1972 and it was labelled Elkhard, with a serial #200XXX. So i guess with a location in Lindey, with a low serial, that could be a 1969-70 cab.