[Dan in Pasadena]

I’d say your choice depends on what you want the finished result to look like. In my case on my ‘55.2 I literally just stopped counting at 50 holes. I wanted the factory embossing patterns on the firewall and not a flat panel.

So we filled each individual hole - NO “overlapping metal”. All the plugs were cut to size and butt welded by mig tack welds, flattened, allowed to cool to avoid warpage, and the next tack or two placed. This involved jumping around from hole to hole but in the end it came out great and I am very happy I chose this option. YMMV.