Perko casts their name into everything they make, and almost all of them have two wingnuts on the outside. Groco uses a single wingnut on a tie rod on some of their strainers.
Both manufacturers size their strainers by pipe size for the inlet and outlet, and often this inch size will be cast into the bronze on the outside of the female receiver.
After you identify and size the unit you have you may find the price of a replacement cylinder more reasonable.
The units on the right are Groco