What did I buy?

I was in a thrift shop this weekend and came across this watch. A little beat up, but cheap enough to be worth it. (I'd rather have a legible original dial than some of the redials out there. Anyway...) The dial and hands look original to me, but I'm confused by the case. I'm familiar with the 5 digit reference numbers, but this case lacks one. I have a few different ideas. Either the number was polished off for the engraving, the movement was recased at some point, or the watch predates the start of their numbering convention. I just wasn't able to find something that looked similar. Maybe I didn't look hard enough. Any thoughts would be appreciated.

A close up of the marking on the caseback.

Would you please submit a closer photo of the dial? It's hard to see the details in the wrist shot.

Here's another picture of the dial. Doesn't show much more than the zoomed in one that bubba posted, but maybe a different angle helps.

Hi again everyone. Popped the back on it and had a couple interesting finds. First off, it seems like this is a UG dial laid over...something else. Likely Waltham, because thats what the caseback says. So that minute track isn't part of the original dial. End of the day I have pretty clean movement and an ok dial. Maybe I'll keep an eye out on ebay for a case. (P.S. - Forgive the lighting, its not great but it's what I've got right now.)