Cutting a hole in sheet metal

Hole saw was my first choice too but my pos wallowy drill press won't go that slow. That's why I suggested the slower hand drill. I'm trying to make a 1.5mm head shim (looks just like a copper head gasket) out of 16g steel. The 80mm is the bore of the cylinders and I only have about 5mm land between cylinders so it's gotta be pretty close. I could probably get away with the "dotted line" method after a few minutes under the die grinder. COMETIC doesn't make this application. If I had a mill, this would be made by now and I'd be selling extras for $40 online, half what they cost new and not in only .020....