Turns out that candymaker Annabelle's acquired Cardinet, maybe in the '70's. Google leads you to sites about both companies and the families that found them.
Some of the formerly Cardinet candies are still produced by Annabelle's. Not Pepper Tree, unfortunately. The closest thing, with similar filling is the U-no bar. I had to try one, just to see if some things really never change. Bought it at CVS.
I think that, if you had a way of injecting some mint flavor into the U-no bar, you'd have something close to Pepper Tree.
Hope this spreads some light on this most important matter.