This Apple-1 got a sticker with number 39 on the back. Next to the heatsink is a round stamp with number 6.
Latest date code of any component is 7650. CPU is 7643,
Bought January 2018 by Jimmy Grewal from German senior software engineer. Only the mainboard. Last owner want to be anonymous.
New owner believe the board was purchased by this German software engineer from someone in Rochester, New York. Maybe 1978 or 1979..
Only the mainboard. But current owner added 2018 period-correct monitor, transformer (Triad F-31X and F-40X from 1976), 80's Panasonic cassette recorder, 1979 Apple II+ Datanetics keyboard and Replica Cassette Interface (but date correct components on ACI).
Owner's twitter account.
Mar 31, 2018: Components