Question on differential seals

I have a 1984 Mondial QV Cab, 54K miles.

I am currently in the process of replacing my CV boots and while at it, I might as well replace the differential output seals. The seals do not leak, even though I am using synthetic Red Line.

Questions to the forum:

1) Look at the mounting flanges below. The surface where the seal touches is worn. Should I use the flanges as is or have them resurfaced? Or should I use fine grid sanding paper?

2) I read in a post to use only OEM seals for the differentials. Is there an upgrade to the OEM seals? Is there a special seal where with an extra lip to seal away from the worn area? Any place in particular that has the OEM or upgraded seals?

3) Regarding the white RTV used on the flange bolt: is this correct? Or did the previous mechanic use standard house hold RTV?

Thank you all in advance.
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In any case, you want to use a fine sandpaper (600~1000 grit) to restore a non-directional, non-super-polished surface finish in the area where the seal actually contacts the hub OD (i.e., you need some micro-scratches to let a little oil lubricate the area). If the depth of the wear is really unusually large, you would have to do some form of restoration, but I doubt you need to that. If you do have a later problem, it's not like it's an $expensive engine-out repair, but can't really help with your decision just from a photo -- so caveat emptor

I think it's standard practice to use RTV there -- otherwise gear oil can leak up the splines and out either the ID or the OD of the flat washer (although the amount applied looks a little excessive as you don't want to extrude a lot of the RTV down the splines).