[Amps] 3-500z amp homebrew question

[Mr Mike]

Hello!
Mike, AC2Q, here.
I am in the process of De-Re-Homebrewing a 6 meter single 3-500z amp I required. In short I doubt it ever worked well, and while it would look good schematically, the construction techniques were horrid.
 
My QUESTION is regarding the RFC that is downstream of the output network, what is it's purpose? And what sort of current would it be carrying?
 
"Typically" in HF amps, it has a value of 2.5mH.
 
Any helpful input appreciated.
 
Mike