2001 gray lemans fuel tank is leaking old fuel at the rear edge. Previous owner had made patch that appeared to be a layer of light colored bondo then a layer of yellow tinged translucent material covering the bondo. After removing the patch Im looking for the correct material to clean the area for the new patch and what type of fuel resistant products to use for the patch. The area is located behind the hold down bolt on the rear edge and appears to be a seam from when the tank was formed. thank you in advance for any help. Our last MotoGuzzi was a ‘76 850T3 so this is lemans is all new to me.