Murray built 64' thru maybe 70'. Bikes built for Sears post WW2 and up till 64' were called J.C. Higgins and typically built by Murray and some Huffy's and just rebadged as J.C. Higgins or after 64', Sears bikes. Montgomary Wards did the same thing with their bikes and called them Hawthorns up untill about the same time in the early 60's when, like Sears, opted for putting their own name on the bikes, although still built primarily by Murray or Huffy. Supposedly, some Monark and Ross built bikes ended up badged as J.C. Higgins or Sears bikes, as well.
I'd say yours is a 64' to 70', and Murray built. Some around here are good at decyphering Murray ser#s around here, if provided with them. I do like that bike. Looks good just as is, as i'd fix the tires, throw on a new chain and roll. :mrgreen: