Soooo, time for an update. Sorry for the picture bombing...
Cream is a terrible colour to try and maintain. It also shows up wear and tear very easily. After all the effort that was put into the car, the scuffing on the leather was a serious issue for me.
For this, I got professional help; no way that I've got the means or talent to get the results I wanted. First off was a complete interior plastics and leather clean. This took them 4 hours to make sure the surfaces were as clean as possible. Failure to prep properly will prevent the dye from adhering to the leather underneath, affecting longevity.
Here's some before and after pics.
While this was busy, I figured I'd give the guy a real challenge; my old M3 steering wheel, just for shits and giggles. To say I was dumbstruck with the results would be an understatement.
After deep clean and leather filler
Tadaa
I now need to figure out how I'm going to get the seatbelts clean, something I didn't notice prior to the deep clean of the leather.