axle size on vintage columbia trikes?
 

I am hoping to rebuild a 1940's Columbia folding adult trike which uses wheels w/hollow hubs and a wingnut to secure them. The drive wheel also connects to the axle via pins that mate to holes in the hub flange. This is similar to some modern trike wheels but I'm not sure the sizes are the same. modern wheels are listed as 5/8" axle diameter. do you know if this is the same as the old school ones?