Ilja
188
sure
Just 10 cases (serial number-wise) away from your shown ref. 3161 - an example with signed crowns is known, as a couple of others as well, but still claiming this 'unsigned' bs a 'fact'. Sure mate. ;-)
As for the E858 vs. E 856 this 1965 catalog page speaks for itself:

Sidenote: there have been times when spare disks were widely available
via ebay, this indeed used to be the reason why collectors avoided the
highly questionable Parking and Worldtime Memovoxes who could not be
identified as true references 3060, 3161 and E856.
I admit that there are for sure still some secrets about unidentified references, but from a historic point of view, one needs to see enough watches in real
and vintage catalog material to be certain those are legit products.
Cordially yours
advocatus diaboli