That is a great pack Jon! Congrats again on an amazing pick-up. The September 1886 tax stamp cancel would place that just a couple months before Goodwin & Co. transitioned to slide & shell packs.
Here are a couple other packs that Henry recently parted with. I love how Goodwin used the seal strips to help secure not only the side seam but cover the top of the pack. In the case of Old Judge the seal strip also wrapped around the bottom of the pack. When they transitioned to slide and shell packs they continued to print this seal strip on the slide although it didn't help seal anything (merely printed). Both of these paper packs date to 1884 (Aug. 1, 1884 cancel on Old Judge pack, March 1, 1884 cancel on Welcome). I believe the Welcome brand would be discontinued by Goodwin by the time they transitioned to slide and shell packs (card distribution).