Rusty sunroof.

Getting it bead blasted is always worth it if you don't have to clean the mess up afterwards.

It should be bead blasted first to remove all rust but this also may hole it. Lead filling is preferable if you get an area peppered with small holes after blasting but you may still need fresh metal welding in at which point, whether you use lead or gobbo becomes a bit irrelevent.

How long will it last? Who knows..depends on the condition of the underside of the metal to a point.

Would a specialist bodyshop be able to re-skin it from sheet metal?

Conor (Conor ) gurgled happily, sounding much like they were saying:

Unless it's a complete gorilla blasting it, it'll only hole if the sound steel remaining there was very, very thin or non-existant anyway.

Chris Bartram (Chris Bartram ) gurgled happily, sounding much like they were saying:

Easily. But as for the cost...

The skin only seems to rust through about an inch forward of the rear edge

- I'd guess at a water trap between it and its frame. The frame itself always seems to be rusty even on apparently decent ones.

I'd imagine a good specialist could cut out and let in new metal - but I don't know of one.

I'd be inclined to send it to SPL. Shouldn't be too dear for such a small panel and you'll know the rust won't be coming back.

If it really is flat then it should be fairly easy to cut out a section from a sheet and weld on a comletely new top. Got to be easier than messing around blasting & filling etc.

It's slightly curved in at least one direction.

Who SPL?

Roof panels usually curve in both, and I can only inagine a sunroof would follow it so water falls into the drains. If the curve is on the frame (which I'd imagine it would be), it's got to be worth a go with the spare panel you have.

Surface Processing Limited IIRC, they advertise in some of the classic and race mags. They dip it to get rid of paint and rust, then use the same primer as is used by OEMs, again, dipped, and then can put a build layer of primer on too.