Several sellers on eBay have helped catching the revision date on an SBB Ae 3/6 II that they sell, when I have been as unpolite to ask them about it. Some have not responded. The sellers that did respond found a magnifying glass and read the tiny print and sent it to me. I have acknowledged them here. The revision dates have a separate column in this table, but I also add it for each locomotive’s text.
If you are such a seller, please feel free to reference any of my SBB Ae 3/6 II pages, it may add authority to your ad. They are summarised here. I have no income from my page, and referencing any is of course free.
What I would much appreciate is the date, like “31.7.44” or “R1 YV 5.2.68” and whether it’s at the right or the left side of the locomotive. Respond within eBay or mail me here.
The “YV” in some revision dates stands for Hauptwerkstätte Yverdon, which is where these revisions were made. The LOKI magazine has a full chapter on revisions [046,18].
I would of course also hope for revision dates on the other gauge SBB Ae 3/6 II models, here.