Congratulations! Very nice find!
Dumpster finds, they do happen, I have one, a Japanese-made 1983 Puch Odyssey, all there, hardly worn original IRC tires, no accident damage, no corrosion or rust, paint in almost like-new condition, and mechanically near perfect.
The apartments here have a community dumpster with two big flip-open lids. I went to the dumpster to drop off a bag of rubbish, flipped open its lid, there was this bike laid out on top of everything else in the bin, gave it a quick look-over and then could not say no to lifting it out and rolling it back and into my apartment where it remains today.