Only marking made in USA. I beleive the manumanufacturer is Truth. Screws hole are 4 3/4 and 3 7/8.
Casey from SWISCO responded:
March 5, 2024
Hello,
Your operator resembles the 39-407. We also offer the 39-406 opposite-handed version. Take a look and confirm that the arm length shown below matches your assembly. Thanks for posting!