The exterior caseback of the Universal Geneve 881101/01 is flat. Stamping/engraving comes in one of three designs, at the top of the caseback and centered horizontally:
1.
STAINLESS STEEL
SWISS
2.
SWISS
STAINLESS STEEL
3.
No engraving/stamping
Curiously, the text does not seem to be consistent to a range of serial numbers. In many images it can be difficult to see the stamping, due to how shallow it is.
We should expect to see the text, ‘STAINLESS STEEL’ in particular, at the top of the caseback, with the leading S and ending L are near the edge of where the caseback shifts from flat to shifting down.
At the bottom of all Universal Geneve 881101/01 casebacks should appear, horizontally aligned,
881101/01
[serial number]
IF the reference 222102/1 does exist, I would expect it to be consistent with the above, and have orizontally aligned:
222102/1
[serial number]
Serial numbers from 2.47 onwards should appear with the ‘ mark to designate breaks for millions and thousands, such as 2’471’848. Prior to this there was no mark, as in 2437995.
These is a very wide range in stamping/etching appearance for the reference and serial number. Some I believe were likely etched later and are not original to the watch, and perhaps the same for some stamping. The earliest watch in this research (226xxxx) appears with etching that is not consistent with later pieces.
Please excuse the poor photos…will add better ones as I get more examples.
The inside of all casebacks is stamped with, horizontally aligned: the Universal Geneve shield logo (near the top), space through the center of the back, then ‘STAINLESS STEEL’ (in contrast to the ‘ACIER INOXYDABLE’ see on the Nina Rindt), ‘SWISS’, and finally the Huguenin Freres logo.
