Now just need to finish getting the interior back in.
Costs? Not much. Some grease which I had: just normal lithium multi-purpose. I can't see why you'd need anything special: it runs in a tight temperature range, at slow speeds with low contact patch loading.
1/3rd roll of RS sealing tape, so under £4.
Bit's of steel and welding: not going to count that. Coffee consumed during whole process probably cost more and even that's instant.
1/3rd bottle seal restorer: say £3.50.
I already had some Wurth Bond and Seal, but let's say 1/ 6th tube. £1.
I'd say under £10 all in? I can't think of anything else.
What I would say however is I was lucky that feet aside, nothing was actually broken. I didn't have to replace impossible to fabricate parts (e.g. all those little sliding feet: 3D print
@depronman ?).
Also, it was a lot of heavy, tricky work. Doing this commercially, for someone else with some sort of warranty? No thanks, I'll leave it to the experts. The price
@Kleynie charges is a stonking bargain and I'm sure can cover the full range of issues without batting an eyelid. I suspect I've been let off lightly with this one.
Would I recommend you give it a go? Realistically you'd have to be very keen, quite well equipped, happy to have car off the road for a bit, have a garage big enough for both roof (with room to work) and the car. Not to mention that whole 'have a go' engineering aptitude. If you have, then go for it.
Also, I'm not sure all the trucks are steel: if others are plastic or aluminum my repair method becomes moot.
So ... if I was to buy another car with a broken roof, yes, I'd do it again. Does it put me off having a car with OSS? Yes, it does really: if nothing else it's massively heavy for what you gain. I think they should have done a fixed pan roof with a retracting blind. Far lighter, stiffens the car, no reliability issues. On the other hand, I might well come to love it if / when the car gets some actual use.
Anyway, once the rest of the interior is in I'll move on to whatever's next. Literally can't remember what that is!