Note the screen coverplate and early (non-spirals) step cone. This instrument is strung with steel strings which appear to be origional.
I tried to fit a set of new, modern uke strings to this instrument and the 3rd string was too fat to pass through the hole in the tailpiece. Please see this note on National Ukulele stringing.
Engraved R.I.B on the coverplate, if you know who this was please let us know!