Gucci does offer repairs and leather color restoration. You must mail to Gucci New York, they do charge a small fee of $200.00.

Has anyone sent their bag off?

I went to the local Gucci store and had mine restored on the outside ...it took about 2 weeks the SA told me it could take 4-6 weeks. The local store sends it to The NY corporate office. I paid $350... But it looks like a brand you purse. Later on I will have the inside redone. I did not have to pay up front , only went the purse came back. The SA will call you first and tell you how much it will cost before restoring the purse.
Good luck !