Old Dies 243 win scuff mark on brass Question

[Ford SD]

Die Question
Leave it alone / polish more or use a bit more aggressive media

Picked up a old set of RCBS 243 win dies marked 74 FL

well Dies are hard to come by Right now and they were priced right
Maybe a bit high with the problems
Bent depriming pin fixed ---(Replaced pin small size)

Little bit of rust in side/outside

used a cleaning brush wrapped in T-shirt patch and used some bore brite polish to get rid of the rust
Looks a lot better but did not want to overdo it

I sized 4 pcs of brass and where the vent hole is there is a small (right at the shoulder)
brass mark the size of the vent hole and have never experiences this before
brass is rough in this spot --Finger nail and visual

Is this normal or should I polish this out (wooden dowl and bore polish )

Also Brass seems hard to size to fl (maybe oversize chamber)--> Should I polish this with 600 grit sandpaper
Die body inside looks feels ok but not to the appearance of newer die sets smooth but with discoloration but not rusty

Thanks
in advance:-?

[DLCTEX]

I have polished out scratches from a number of dies. Use the 600 grit .

[Ford SD]

Well tried rubbing at it with the corner with a wooden dowel(dry nothing on it),
all i did was put sawdust in the vent port

went looking for sandpaper --the first emery paper i found was 400 gt

put a strip on a wooden dowel and worked slowly at it for about a min by hand
(bty not a tight fit) trying keep in the corner and doing a bit in the lower part of the die where there was some discoloration

clean die and tried another pc of brass -- spot gone but die a bit on the force full side

So used a ps of brass and some bore brite polish on in it 1/8-1/4 up down at a time till fully seated
keeping polish away from the shoulder / neck area / repeat

Looks a lot better no discoloration mirror smooth from one angle and small dull marks from another angle at the bottom of the die

Brass still seems hard to size to fl using RCBS lube---->easier than before (maybe brass from a over sized chamber )-->new rifle

need to find a neck die if shot a lot (back up cyote/ deer gun)

Thanks