This discussion relates simply to whether some pieces were manufactured prior to Vacheron Constantin using reference 4072.
One steel Vacheron Constantin, with case number 262241, was sold by dealer with notes indicating a V295 movement and is listed merely as a “Chronograph” on the Vacheron Constantin Certificate of Authenticity with a manufacture date of 1938. That there is no note of reference is not overly unusual, as Vacheron Constantin introduced reference numbers only in 1938.
Although not listed as a reference 4072 on the Certificate mentioned above, the book MICRO – Royal Vacheron Constantin does refer to 262241 as a reference 4072.
Aside: this example has a sector dial, which I have not seen on any other steel Vacheron Constantin 4072 examples. Additionally curious is the font of the numerals in the two registers, which differs between each other, something we do not see elsewhere, as well as the color of the registers.
Case number 262237 is noted as reference 4072 by auction houses, and when sold it was noted that a Vacheron Constantin Certificate of Authenticity was included (I have not seen the certificate). I would assume that the reference was listed on the Certificate if the auction house included it on the lot notes, but of course it possible the auction house added the reference without it being specifically listed on the Certificate.
I do not yet have confirmation whether all 4072s had reference numbers, which might help provide more information on this piece. I will update if I receive that information.