Looking for Info on a WWII JLC Cal 450 Watch

Howdy gang; picked this one up recently to be resold but was looking for some info from the experts. This appears to be a 6B from the early 40's but doesnt have military markings. Is there a way to identify it more closely? It has a TON of service markings in the caseback, assuming from it being issued to personal and regularly serviced as a result. Perhaps this is all delusions of grandeur on my part, but Ive only really seen this reference in military ilk and not civilian. Any experts out there know better than I? Watch is all steel and has a cal 450.

Really nice original piece but would like to have it serviced. Any recommendations for these?

Attached Images