I'm all for keeping old things around and that includes Flash stuff (look at my user name). But Shumway is super dead.
I believe there are more active projects going you might want to check out if you're looking to keep Flash alive/around.
Alternatives:
* https://get.adobe.com/flashplayer/otherversions/ (yeah, still works!)
* https://github.com/lightspark/lightspark
* https://wiki.debian.org/PepperFlashPlayer