The type of tube is called a numitron - a few companies made them Apollo / RCA. The bad new is that the filaments burn out but you can find replacements pretty easily on eBay if you're patient.
As far as the clock itself - I've never seen one like that. Good find!
Hello, I am a new guy here and I come to this site from time to time from searches. I came across your post here and was wondering if you fixed up this clock and how you like it? I have a book that this clock is featured in, but slightly different model. I have fallen in love with these old clocks. I also was wondering if you would be willing to part with it as I am interested. I am sorry if this is intruding in anyway.