ser#s for most any bike are located in one of 3 places. on the bottom of the bottom bracket shell, on the left rear dropout or on the side of the head tube. without a pict of your bike, i can only speculate what year it is, but i will tell you that before WW2, they were called elgins and after WW2 untill 63' or 64', jc higgins. after 64', sears dropped the jc higgins name plate and used their own name, sears. most jchs were built by either murray with some huffies. european jchs with 3pc cranks and chainrings sspelling out the jc higgins were promarily austrian made, perhaps by steyr or another maker. odds are, late 50's to 64', but without a pict, thats as close as i can get. as for decoding eh ser#, would need to know if its murray, huffy or other built. good luck!
p.s. i actually got one of those austrian built jchs myself. a black 3speed with white pinstriping and the same chainring you got, sans chainguard.
