Brake Master Cyl (Cont.)

[SpeedSites@aol.com]

Ok, so I got the thing apart and it looks clean... 

then I notice the RUST beneath the portal that leads to the fluid reservoir. 
I assume this means I should do a mild honing? Or will a brisk cleaning with, 
say, a rough rag do it (the rust is light and loose)? If I need to hone, 
should I use some light oil while I hone?

All input appreciated on this "auto mechanics 101" forum. 

PS: A 1/2" allen key is a tough find, but Sears came to the rescue for $9.