I tried aircraft stripper on the wrinkle black engine paint on my first Guzzi. A 2001 Rosso Mandello. Guzzi would let you choose from new black engine cases under warranty, or a "settlement" of some carbon fiber accessories. I could not see tearing apart the engine , just for the cosmetic issue, so I chose the CF accessories.
I was able to pressure wash most of the wrinkly stuff away, a few stubborn areas came clean, with aircraft stripper applied by brush, then scrubbing with small brass brushes, and more power washing
I spray painted the engine cases, after carefully masking off where I didnt want paint, and then painted it with satin black rattle can paint made by VHT, that was chemical, and heat resistant.
It came out real nice, IMHO, looking like the newer smoother finish Guzzi applied to the 03-04 bikes.