71 orange on orange Demon A31

I believe that the Sequence number refers to the assigned Order for a particular car. It can come from internal departments, for one offs, promos, etc. or as dealer bank cars - building a run of assorted cars for general sale, and orders from dealers for custom-ordered cars. From what I understand, these normally just used the next higher number. It is possible that some may have never been built - cancelled orders. Some special runs may use a sequence of numbers not in the normal number batch - eg. use a letter as the first VON character.

The VIN number refers to the intended order of buid on the assembly line. This sequential number is unique to all vehicles at the plant