You might try removing/disabling the set error capture step and check to see what error message--if any you are getting.
IF g_prime_name is a global field, you don't also need to use the $prime variable. you can simply use:
enter find mode
Set Field [Evaluation::prine_contractor_name; evaluation::g_prime_name]
Perform Find 
That won't explain why it's not working. It's just simpler code.
Other things you can check:
- In layout set up of the layout you have up when this script runs, you should see "evaluation" without the quotes in the Show Records From box.
- Neither Enter Find Mode nor Perform Find should have [Restore] after them. (Enter Find Mode could, but it's better to use set field as this makes it easier to tell what criteria are being specified in the find.)