Tried two of the local big truck stores (both have been around longer than me - 38 years), they took the spring and tried to match...no go.
Tried ordering a set of springs that were listed for Euclid truck with Wagner 15 x 4 brakes, but the wire was WAY too heavy...
I'm still lookin'...
Anbody got a '52-'60 1.5 or 2 ton that they're parting out ?