[R-390] Restoration questions

[Johnsay Johnsay]

Hi All:
I'm currently in the process of refurbishing a '58 vintage Motorola with an EAC IF strip.
I've finished cleaning it up and going over the mechanicals.  So far I'm well pleased as it's quite sensitive and mostly everything seems to be working fairly well.
On this  unit I've noticed that the function switch has an unmarked, extra detente beyond "CAL".  Functionally it behaves like MGC.  Wattup wid dat?  Secondly this unit seems to have a surplus of gain and readily overloads unless one rides the RF gain.  It's particularly annoying on CW.  Is this normal or an issue?
Other than a rough check of the front end  and checking tubes I really haven't gone through an alignment.  So far I've checked tubes in the if strip and replaced C503.
BTW, thanks to those who assembled the Y2K manual,  what a resource!
John,  W8KX