last day of 1970 chrysler vehicle production???

hi there guys....i have an interesting little question that i cannot seem to find an answer for. My car is a 1970 plymouth duster, the vin confirms it as a 1970 model year as well as the factory items inside as somethings were not avalible on the 71' model year such as the certain bench seat pattern i have. BUT, i have come across this website: http://www.extrememopars.com/moparpantherpinkduster.htm according to this, the last day of production was july 10th and according to numerous vin decoders, my car was built on July 30th! (after the paint code, there is a very clear 730 on the fender tag) how is this possible??? PLEASE speak now if you have any insight thank you very much!