Travel, Teach, Live in China
As far as I know John you must be married for 5 years amd life in China for all of those 5 years before you can apply for a Chinese sponsered visa. You are suppose to still have to go through the same process to get a work visa. That is what I was once told after I got married to my wife. I am thinking from what you have told us about destroying your old visa that you also destroyed the only copy that you had of your old work visas. I would think that with a lot of effort you should be able to track down copies of your old visas from the different PSB offices in those different cities to be able to prove that you have been in the country all this time since your marriage. I do not know how efficent the head offices of the PSB is and if they would have in their computers the places and names of your old employers. Good luck with your efforts here, Keep us updated as to what happens.
KJK