1931 Auburn 8-98A Tappet

I have been chasing for about a year and a half a sticking valve on my Auburn Speedster and it would only occasionally stick.  Unfortunately it really stuck this time and when I removed the plug it was stuck open.  I gave it a push with a wooden dowel and just pushing it by hand and it snapped back in place.  That was good.  The problem was that as it turns out it would no longer open because the tappet is gone.  You can see the disc is missing by comparing it to the one to the right.  Not sure if that is going to have caused more chaos in the engine because I don't know if it could make it to the pan without beating up other things.  The area between the lobes of the cam looks bad but every space on the cam has the same ugliness so I guess that is normal?   In any event, I am definitely going to need some valve train parts.  Anyone have a source?