I have two 686 no-dash, and I can confirm ONE of them to leaving the factory on May 22, 1986. I purchased that one from a LGS in CA in August of 1986. Still have all the paperwork/box/receipts. Both have "AUE" prefix.
The 3rd Edition of S&W would also put your 686 in early 1986, likely between Jan and May 1986. BTW, the 4-digit Spec. Ord. number will give you the year (1st digit) and the next 3-digits the day of that year. Most of the time these are rather accurate, but not always...