While you can scale close from photos you would be better to go from measurements where you can.
Obviously you want the shields to look like originals so best to get it as close as you can otherwise you could use any old thing.
No ones going to notice whether they are 10mm or 3/8" holes but a different pitch will stand out.
As Momus says 1.2 =18# and 1.5 = 16# however the US may run different specs?
Perf sheet is usually punched out a row of holes at a time, you can get perf made in a turret punch but they will only punch one hole at a time, even though the sheet will be moved around by CNC it is still a slow process and needs to have the right size punch fitted to the machine.
Laser cutting is great for cutting out intricate shapes but there will be a small dag where the laser stops and starts in the hole but it is usually very minor. A plasma will leave a bigger dag
It will produce what ever size hole you draw, any difference is not worth measuring
My CZ heat shields I have laser cut in 1.2
Plenty of laser and water jet cutters these days, water is slower and best suited to thick materials
Most will charge you a programming fee
I get stuff laser cut all the time and draw up my own CAD files, can easily draw up your perf if I have the dimensions and get a quote for you or you can use the file to get your own quotes