I did find the number but it is difficult to read. Just looked at it again and it appears to be 4017. Looks like it was hand tapped in between the pulls.
The pulls on yours looks just like mine.. On mine it looks like the pulls were originally chromed but are now a bit rusty and there was a button of bakelite or something similar on the ends of the pulls. looks like it was either brown or red.
The finish on your machine looks great and I would keep it that way. If I restore mine I would like to attempt to duplicate the original finish. The woodgrain paint process that Curtis used looks outstanding but I am an original finish guy if giving the choice. Thanks for posting the pictures!
Tim