Rolex bubbleback - need information

[Voltime]

I was handed down this Rolex bubbleback and despite searching all over the internet...I can't find one with a dial that looks just like it. So, I'm having trouble nailing down any information about it other than it likely being from the 40s. It currently is inoperable and I might see about having it repaired, but I really want to know more about it first. The local dealer said he had no information on it and wouldn't work on it. Any feedback or information is greatly appreciated.