While I don't own a 206 (yet), I have come across a lot of information concerning the 206. The 206 is a design licensed by Singer from Pfaff in the 1930s, with the stipulation that it not be identical to Pfaffs machine. (We're more than likely talking about the Pfaff 130 here) It's thought this is why Singer basically ground a flat edge on an industrial needle and called it 206x13. A 1962 lawsuit bought by the United States against Singer gives us the info that the 206 was developed in 1934 and manufactured at Wittenberge in Germany until "the opening of WWII."
The suit also states that since the end of the war, the 206 has been produced at Kilbowie in Scotland in several models, and that the 206 was first imported and sold in the United States in 1951.
I was stunned to find out that the first 206 models featured the funky Pfaff mechanism. I thought that would be an easy delineation between German and British produced models. But it looks like the bakelight faced bight control, as used later on the 306s and 319s, was introduced AFTER the machine was being sold in the US. So, for you 206 owners out there, do the following assumptions make sense to you?:
1.) German produced 206s are cast iron, and heavy and use the funky Pfaff bight control exclusively. Produced only until the onset of WWII.
2.) British produced 206s are aluminum, but can carry either the funky Pfaff bight control OR the later Singer designed bakelight control.
3.) There are industrial model 206s as well, produced after WWII at Kilbowie.