How do you make louvers

Use aluminum sheet. Use a knife to cut the open ends of the louver first. Then make yourself a tool to press the louver open. I once did this using a leather stamping tool. I found that if I worked with the piece of aluminum on a bed of modeling clay it worked out well. I used a rolling pin with a thickness gauge to roll out the clay to a 1/4 inch.

I was going to suggest the same thing. I used ground-thinner louvers from a model train shop to replicate the cooling vents on a 1932 Chrysler Imperial.

  VESPA BOY - WHATTA PROJECT!!!! Knowing the scale would help but here goes . I make louvers for machines and things I do for attorneys ,but the scale is usually 1/16 or larger . What I do is use the louvered panel from the side of train engines .I use baking foil or if I need it heavier I overlay it . Just make sure you have the material clamped down tight and have a very sturdy burnishing tool ( Mine is a rounded off (slightly) scratch awl ) When your finished CAREFULLY cut the louvers open . The best louver mold I,ve found is from LIONEL and larger trains . If you need smaller then use panels from ATHEARN engines in h.o. .      tankerbuilder