I'm gonna guess that car #1 has been repainted--very thoroughly but repainted. Reseda didn't come out until E21 days, so some few years after this car was built. Take a close look at the data (VIN) plate--it's mounted upside down, which may mean it was removed during the repaint and then replaced backwards...just a guess though. Also look at the top of the front strut bearings--it looks like a ring of Reseda paint on the rubber lip of the bearing where it touches the fender.
Usually CKD cars are shipped with the body shell completely assembled and in primer; at the assembly plant the rest of the sheet metal is attached, the body is painted and then running gear and trim is attached. I'm sure the folks at BMW Classic could tell you how CKD BMWs were assembled in Portugal, Israel and Uruguay. You might also check with Munich to see if Reseda was used on another BMW model in 1971, and if the Portugal-cars were painted locally, could it have been a special order.
I agree with Son of Marty -- what you see in the trunk of #2 is sloppily applied contact cement. If you look closely, the fabric that's applied to the inner fender wells on those Portuguese-assembled cars is quite different (taller and laps over the seam) from what the Munich factory installed. And it appears to be the same thin material used on the trunk floorboards, not the thicker, backed material used by the German factory.
Even though the color probably isn't correct, I think #1 is the best of the three. Let us know what you think after you've seen 'em in person
mike
PS--a 1600 should have silver side and center grille bars...none of these do.