So with the roof and old scuttle removed and everything cleaned up, it’s on with the new panels.
The scuttle is only available as a Heritage panel in a one-piece pressing with the windscreen frame, but since the rot in this panel is usually worst in the bottom corners of the screen where it meets the wings, I believe it’s common to cut the windscreen frame section off and only use the scuttle (maybe even just the sides of it). This saves a lot of work if the rest of it is sound, but as my windscreen frame was rotten in the top corners too, and I was also replacing the roof, it made sense to fit the whole thing.
First job was to strip back the paint from every edge that was going to be welded. I planned to spot weld most of it (all 4 sides of the screen, the top of the A-posts, the front edge, and the lip of the scuttle vent). The only MIG welding required is a line of plug welds on each side along the wing joint, and 2 small butt welds to connect the lip for the bonnet seal.
I was a bit worried this panel would need a huge amount of fettling to get a good fit, but was relieved to find it all lined up perfectly first time. Even with the old roof and scuttle removed, the A/B/C pillar side structures retain a surprising amount of strength, so make great datum points for checking the fit. With it all clamped in I temporarily set both front wings in place to confirm they would also line up OK later on, and it all looked good.
From the factory, the panel is supplied with this central strengthening brace still in place, no doubt to prevent it being crushed during shipping, but also helps to keep the correct shape when fitting.
Much of the strength of this section comes from this joint at the top of the A-pillars, and I probably spent most of my time getting this area to fit snugly to get the best welds possible. The lip at the top (just above the oval hole for sunvisor bracket) was actually vertical as supplied, but needs to be bent down to be closer to horizontal for the roof to clear it, and the end is then welded to the end of the lip on the side rail.
For the joint at the outer edge of the A-pillar I again used 2-pack automotive glue to bond the new panel in place (as I had done with the similar joint on the C-pillars), keeping it firmly clamped down whilst it cured.
I had drilled out a lot of spot welds in this area when I removed the old panel, and I tried to make sure I put them all back in!
With the welding done, I etch primed all of the exposed metal, and it would get a couple of further coats of rust preventative paint (although without a leaky sunroof to worry about anymore it hopefully won’t be necessary!). The flange at the top of the windscreen was masked up here since it was wearing a coat of weld-through primer, ready for the roof to be spot welded to it later on.
And that’s that – a job I had been dreading for ages, but it turned out to be refreshingly straightforward.