Single Bed

This bed is of very dark wood - not sure what type.  There are glass castors on the bottom of the legs and inside writing that says ONWARD and something else I cannot make out. The frames are solid wood and there are no slats but and actual mesh spring foundation attached to a wooden frame that has various stamps on it.  It states - Guaranteed Gold Metal Bedding, then a little further down the number 151, then a little further down it says No 0 HERCULES, then a little further is says TM REGISTERED with a colored oval picture and a little further down still is stamped the number 33.  When made this bed was actually a single bed but by today's measurements a single mattress is just  a little too long to fit - about 1 to 1 1/2" too long. I would be very interested to know when the bed was actually made and it's monetary value.