Hi Christian!
I had the same problem with my blaster when applying for EIB- specifically the print lines on the back of the blaster and D ring. I'd recommend putting on a coat of Bondo. For my D ring, I removed it, sanded it down as best I could, gooped it up with bondo, sanded back down, and repainted. It was probably the most difficult part of the blaster for me to get right. The flat surfaces, like the back of your blaster in the pic above, will be very easy to fix with a light coat of bondo, sanding, and repainting.
My EIB thread below, if you wanted references of what a blaster with visible print lines looked like before and after EIB approval.