Well you did get some good ideas by looking at already existing maps, but the 1500 one is sloppy on many regards. If I were you, I'd just go with the rivers/political basemap, and begin from scratch. It's going to be relatively annoying (believe me, I did many thing from scratch in the maps I did for OTL depository) but eventually, it's gonna pay off in quality.
I could do some attempts myself, but it's going to take some time.
Borders, except for the Lorraine area, didn't really changed between 1547 and 1520.