I have had two motorhomes self destruct due to nature taking its toll on poor design/construction so have decided to build one. I bought a 1983 Grumman-Olson step van with an aluminum body. The sheet stock is 1/8" thick, and I have six windows to install. Flanges are relatively small so it needs to be pretty precise. I don't want to cut it with a jig saw if I can help it, can't find a nibbler that will cut stock that thick, plus the rivets may be a problem.
I would like to do it with a router and a jig but have never cut aluminum with a router. The windows have a 2.5 inch radius corner so a router would be fine. But..........

Its not like you get a second chance when doing the side of a vehicle so am a bit apprehensive.

Lets hear your suggestions based on experience.

Thanks, Larry