: Sinn revised a number of decommissioned watches, which were
: advertised for public sale in German newspapers and magazines.
: Off the top of my head the issue markings are usually still
: intact, but I wouldn't be too surprised if they were
: removed/obfuscated as part of that revision process for some
: watches.

That's the reason I find a lot of these Bund heuer in as new condition on the market recently. Many have not the markings. Sincerely I thought they were fresh assembled repros.