Help on Lighter I Dug?

Having followed a dry creek-bed one early summer, I came across a single bottle and began looking for more in the area.
Crawling out of the thorny vines and branches, I found myself in a small opening under the trees within which bottles were scattered about.
Sadly most were 1960s on, but I found a number of mounds that were household dumps from the '40s to '60s.
So, over a period of days, I dug.
Under extremely low branches and using one of three hand-trowels (one broke!) from my pack, I ignored mosquitoes robbing me of my life-force and dug up the main body of this lighter, among other things.
At first I thought it was some mini sign for something. It was damaged, so I repaired that (photos won't show it,) and the next day I dug what I realised was the top to it. (Yay me. LOL.)
I know that the building still stands, now a paint-shop.

I'm guessing late 1950s but dunno, and think that it was given to employees.
It has debossed in the metal, Wellington Balboa and Japan.

Help?