Somerset and Cambria still use their Thunderbolts.
Well Somerset has one offline the other one works though.

^The one above is out of service, while the one below is still in use.V

Both are in Somerset Boro.
And here is Cambria's T-bolt in Jackson Twp.
Btw when I went through DuBois I saw one on a side street from US. Route 219, along with 2 STH-10s.