Currently working and as a matter of interest was tested over a 19 hour period and gained approx 30 seconds. It will need a service to keep absolute perfect time. The base metal case is 51.1mm in diameter. 1944 Hamilton, Grade 4992B, Model 5, 22J, 16S, stem set, stem wind, 6 adjusts with date serial number on movement 4C90487. Military serial number AF42-30629. Case back has a lot of wear to the centre. Dial has 2 marks as per photo.