They were made from the 60's to the early 80's. They are TTO one piece razors. I believe this to be the first generation which corresponds with the Erfa Rasant Generation 5 and shares some parts with it.
The topcap and adjusting plate are chrome plated (I have no idea whats under the chrome) and the rest of the razor is aluminium. Its has the same sort of lather channels that the Erfa/Progress (see the insert in the fifth picture below) has but has drain holes in the bottom.
The middle plate is the same one that is used on the Generation 5 Erfa Rasant except that there is a cutout on each side that accomodates the center bar, which expends through the doors. The handle is the same, albeit longer.
The TTO knob has a dial numbered 0 to 3 and really just opens and closes the doors. The middle plate is spring loaded so it keeps the blade under tension against the doors - A very simple yet effective system.

This one has seen its fair share of shaves and has some plating loss on the outer edges of the safety bars, a few spots on the handle and some fading of the TTO knob. It's also a bit more aggressive then the Gen 2 Version.

(Clicking on the instructions towards the bottom of the page will open them in a new window)

How does it shave?
What I expected - A mild and no BBS Shaver
What I got - A pleasant surprise. This is a medium to mildly aggressive razor. On its first outing I managed a BBS in my normal 2 Passes plus some touch ups.

The Instructions (That came in the strorage case.)

Translations: TOP IMAGE: Care After shaving, relax the device and rinse off any soap and beard residue in warm water. From time to time, it is recommended to thoroughly clean the opened device using a soft brush in warm water. Storage A stab-proof leather travel case and a plastic case with a blade holder have been developed for this purpose. RRP in leather case M18.50 RRP in plastic case M14.50 ELN No. 13912530 VEB Brillant Razors BOTTOM IMAGE This one-piece folding razor is rust-proof, adjustable, and suitable for all stainless steel blades. Use Turn the adjustment knob counterclockwise. Open the razor, insert the blade, close it, and turn it to the zero position. Avoid overtightening to avoid damaging the razor. Now adjust the desired cutting power according to the numerical scale by releasing the tension. If necessary, return the released blade to the center for an even cut. The spring-loaded pressure plate then ensures that the blades remain in place. The blade remains in the razor's ready-to-use position until it is completely used up.