Blackhawk New Britain Socket set box AGE?

[Lump]

Recently bought a Blackhawk box, painted red. Label inside lid marked "The New Britain Machine Company" and "Blackhawk Hand Tools". Looks like it was made for a 3/8 drive ratchet and socket set. I found it filled with several name brand ignition wrenches for cheap. But now I see that the box is really pretty good shape. Can anyone tell me the approximate age? My guess would have been 1960's, but that guess is pretty wild. Here is photo, still dirty and not yet wiped out or anything.
<a href="http://s297.photobucket.com/albums/mm222/Lilump/Tools%20n%20Garage%20Stuff/?action=view&current=Blackhawkbox.jpg" target="_blank"><img src="http://i297.photobucket.com/albums/mm222/Lilump/Tools%20n%20Garage%20Stuff/Blackhawkbox.jpg" border="0" alt="Blackhawk box"></a>

 

[dieseldodge01]

Looks like a box for the 221-B socket set. Would have 6 short socket and 8 deep, a universal, 2 extensions, breaker bar and a ratchet. The set is in my 1970 Blackhawk catalog. If you ever decide to sell PM I would be interested.

 

[lbgradwell]

It has to be 1952 to 1972, but beyond that I just don't know...