[Henry Schmidt]

I had a though about my earlier post. My comment about head studs was based simply on the pictures you posted. The lower studs look like coated Dilivar. It is possible that some previous builder replaced the Dilivar with Canyon "Super Suds".
They are a coated steel stud designed as a Dilivar replacement. If you test them with a magnet you'll know. If the are magnetic, you're go to go.
Just a thought.