Your car would have had a late November date on the tag. I've collected vins from December '70 built cars trying to figure out what my own tag date should be, since my fender tag is too rusted to decipher in that spot. Here is what I've found...
JS23R1B228932-C01=Dec. 1st (Monday)
JS23R1B242313-C11=Dec. 11th
JS23N1B244055-C14=Dec. 14th
JS23N1B245843-C1?= (my car)
JS23N1B249446-C15=Dec. 15th
JS23R1B251607-C15=Dec. 15th
JS23N1B275920-125=Jan. 25th
For your vin beginning 225xxx November 24th-28th is reasonable, B24-B28, easiest thing to do is watch ebay and other auctions for vins and tags.