I have drilled out my scuttle rivets as well, for ease of access., on a previous scuttle. I have a newer one on now, and intend to do it again.
When I can, I would like to replace the firewall with a new piece of a thicker gage sheet.
In that picture, LHD S3 has indicators under the headlamps whereas a RHD S3 I have seen does not. I am thinking these were USA DOT compliance additions.
On the S3 photo, I count 24-25 rivets. My scuttle has 24