More progress today, got the first couple of cross beams tacked in place and so far it all still fits!
I was planning to just have one vertical beam in the middle (along with one on each side) but the bit where the chin panel bolts on juts out more than I thought it did so we’re going for a total of 4 verticals…a bit more cutting but no biggie, and might mean I can use slightly thinner sheet to bridge the gaps (or something).
The centre verticals are just clamped in place in the last pic (hence the great big bit of angle iron to keep things aligned) but they look to fit ok and will get tacked in place next.
Once actually under the car the “longwise” sections (i.e. the continuation of the verticals, in line with the car) will need to deviate from equal spacing to allow clearance for the sump, gearbox etc but there should still be plenty of bracing to ensure it’s nice and study for when I grind it over kerbs, rocks or whatever 😉