Jeff, first congratulations to the 20.000 posts an impressive number !
After the recent discussions around our well loved Sifferts I thought it could be helpfull to classify the different development stages of reference 1163 T.
First the Chronomatic:Chronomatic on top of Heuer and unique case with less integrated pushers.Hours subdial showing 3,6,9,12.(MY1969)
Mark 1 would be the all steel hands, steel indices and Autavia on top of Heuer, slightly more integrated pushers, Autavia typo showing the flat V. (MY1970)
Mark 2 new indices with black inserts, steel hands with black inserts, Autavia typo showing the pointed V, new more rounded and integrated pusher cut outs.(MY1970 1/2)
Mark 3 introduction of the blue tipped brushed steel hands(MY 1971)
Mark 4 hour subdial numbered 1 to 12.(MY 1972)
Mark 5 introduction of white painted steel hands with black inserts matching indices inserts.Larger pusher cutouts.(MY 1972 1/2)
Also was the thickness of printing on the tachy rings slightly different.
I have not seen any Siffert 1163T in Heuer catalogs after MY 1971/72, hence we could say the Siffert was only advertised and produced between 1969 and 1972.
The maximal production by modelline was 2000 pieces a year, the split between black dialed so called Derek Bell 1163 MH would be possibly 50/50.
Therefore we could guess that between 1970 and 1972 around 3000 Sifferts were produced.
Any thoughts ?
The last mint Siffert I have seen on offer, was sold at the Munich watch fair two weeks ago for 4500€.
Prices on the raise, good quality or even new old stock ones have become very very hard to find and deserve a hefty price premium.
Cheers
Arno
www.heuerchronographs.com