Jeff, the 10CC or 10CG are the first digits of numbers that should be on the engine, but I don't remember where.
Two things to note, I and a freind who has more experience with Spridgets than I were talking about the early 1098s, we had both heard the rumor that they are weak in the crank/main bearing department, but we have never had or directly known of one that has failed--if you want to drive it moderately it should be fine, if you want to go fast you should put a 1275cc engine in it any way.
Second, lots and lots of these cars have had engine swaps, when they were used cars people ran them on the cheap and tended to pick up used parts to bolt on when things went wrong, because there were usually plenty around in various states of disrepair to cannabalize.
So determining the exact year won't necessarily determine what motor you have. As mentioned, best is the check the engine serial number, someone here should be able to tell you where it is.