Tried that last night as I have a "Diesel" Ymos gas cap(doesn't say it directly), but looks exactly like the one in the Wikipedia photos.
I only have one access holes on the backside, while the photo has two and cannot see anything that the screwdriver will catch. Also the instructions dont say if the cap is locked or unlocked. In that case mine is locked, so it's a useable one.
I have one other Ymos one, that has the later fat key (with no access holes) and 7 HUF ones that are no good(as no key for those but they are all locked) Are these considered scrap?
Thanks for any assistance.
Happy Holidays to all!
Walter Klatt
1967 220SL-diesel