sube imagenesBell & Ross were fast out of the blocks when they started in 1992, offering re-branded Sinns as you picture. This was one of their earlier offerings, probably not from day one, but certainly after it was offered by a few others.
The case was used by Arctos for their Bund in 1982, by Heuer for the AMI in 1985 (and Lemania offered their own-brand version of the same watch), and by Tengler for their Bund offering later on in the 90s.
Sinn certainly improved the case, and offered shrouded pushers, increased WR and titanium versions later on, culminating in the EZM4 Achilles.
However, I don't know when they first offered it.
Perhaps someone else can help.
I would add that the Sinn 156 was reputed to have been developed to try and win the Bund contract which was one by the first of the Lemania 5100 Bund chronos, the Porsche Design made by Orfina, which was issued since 1979. the PD uses a different case. It stands to reason the the 157 post-dates that contract.
It is also certain that the case was not developed, designed or made by Sinn, as it is found in these other watches. It was most likely a bought in component, assembled by Guinand, as all Sinn watches were at that time.
So who made it, and when, is anyones guess between 1979 and 1982.
wus
