Last week I had some time to work on the OLED. All the resistors, capacitors and the breakout board finally arrived (they arrived about 4 weeks earlier, but to a different address) and I originally planned on directly soldering the flat flex onto the breakout board (and later the elongated pads on the PCB.

What I didn' notice in the Aliexpress seller's images was, that the flex is meant to be inserted into a connector, and has a thickend end. I tried to scrape it flat, but soldering it directly to the board was still impossible: the remaining height difference in combination with the solder resist was still to high. So I ripped an IDE HDD cable apart and tried to bridging this gap with bare copper wire. Which worked, but the .5mm pitch, in combination with a .5mm² wire made this procedure very short-circuit-inducing. So I finally gave up and bought the slimmest FPC connectors i could find. No datasheet though - so again it will be trial and error getting those to fit. I'll probably leave the (extremely) elongated pads there, so I can freely position the connector on the first PCB prototype. (the strain relief pads wont be soldered; maybe I'll glue them)

(i had to write something down - otherrwise this project would become completely dead. it isn't that I don't want to work on it - but i have most of my stuff 300km away, and when i am there, friends and family also cant be neglected)