This was taken many moons ago, when a very fortunate fellow acquired the mint condition Marine Chronometer for a song from a family in the SF Bay Area, and he kindly brought it by to share it with me as he knew my penchant for UN and in particular their 1846MC line.
I was able with a poor quality camera to at least capture the moment for posterity, with my 150th Anniversary RG piece lying on it.
I suspect you're special piece, is a truly rare one of 3 ever made???
Looking forward to hearing and seeing more on that beauty!
Cheers,
Tim