1870 5 Cents Variety

Looks like a raised / narrow rim.

Besides the possible 7/7, what other specific "characteristics" do you see in the photos that we don't, that makes it a variety? Many Victorian 5 cents have die clash marks or die cracks, mine has both.

What does the portrait number have to do with the reverse?

Charlton or any other list does not have all the possible repunches that were done on Victorian coins. Probably every digit on every die has been repunched at some time. The more it is repunched, the more it can widen. Also, wear will make the letters wider as the higher part wears down.
My 1870 has the same look of the 70 as yours, with a weak 18 which would need to be repunched eventually.
Please post photos of both sides to see if there are other anomalies.