After drilling through the sound spot welds in the centre and prising away flaky metal at the sides, the scuttle panel is off.
Before removing it, the central measurement between the top and bottom of the windscreen hole was 415mm. I had sound metal to measure from. Left and right of that the scuttle flange was crumbly and fell away when the windcreen rubber was removed.
Is there any reason why 415mm isn't the gap to the left and right? The bulkhead flange seems to dip down with the scuttle flange standing proud but I didn't have sound scuttle to measure from.

Thanks in advance,
Adam