The Stanley wood boxes I've handled have all been made of chestnut.  The
chestnut blight of 1906 put an end to that.  I think it is most likely
your box is authentic (roughly, from memory, finger jointed, about 1/16
inch thick stock).  That's what a friend's 3rd model 45 came in, and
another friend's dowel machine. 

Mike in Woodland