In the Scuderia Filipinetti book I have the wheels do appear to be gold - at least at some races. I've decided to leave them alone.
As for the BonGrip logo there is a line over the 'on' and 'rip' and another line under all the letters with a break where the line intersects the leg of the 'p'. I can't see making up decals for that but some day when I'm doing livery for something else I might give it a shot - if I can figure out the proper color of the lines.

This model looks so good to me that I'm tempted to replace my GMP MK3B.