Weirdly I found it quieter with the soft top.

I've changed both types with the column in place, the bearing one is pressed steel and I dimly recall peeling its remains out.

Do you know how much space there is between it and the metal? Stiffening is always best done by increasing the thickness, so if there's room for some battens that's the route I'd take. Failing that, if you've got the resin out, add some glassfibre?

If you used spray contact adhesive you did good, putting it on both surfaces does not go well! (Probably ok on the flat bits but there are no second chances when you get to the interesting bits).

Why not talk to ARB?

As @brianp38dse says, no. It only takes 3 or 4 cubic feet to inflate the average car tyre from flat, and the ones I've used would take a couple of minutes to get there, so at best 2cfm. You need at least 6 times that. If you had an air tank you could fill that slowly and then get a few minutes...

I wouldn't drive it with the cover off! Not unless you like the taste of gear oil.

Good point. I had a look back at previous questions, and post #4 here https://www.landyzone.co.uk/land-rover/lt76-layshaft-im-confused.334034/ might be useful. James Martin used to be our gearbox guru!

And a ps. If the chassis is shot then the bulkhead probably is too, and it's a lot easier to work on off the car.

I did wonder if you had. Could it just be a bit of eccentricity on that?

Have you renewed any other parts?

And another. With a bit of thought one person can lift it all off, and it takes up surprisingly little room.

Are you mixing my pic with @Chonker's? Also, if you look at his last post there's a link to a fairly depressing video.

That's not good. On the one hand sounding like a big end but not continuous. I'd check the oil level, if it's low then I can imagine it sometimes suppressing the noise/sometimes not. Then drain it and see if there's metal. Possibly something happening under the timing cover, so is it louder...

Another thought. Did you have to disconnect an earth from the gearboxes? If you did, and it was the only proper one, then you might have seen a short?

The missing bits of this spring made a fair old bang, and I'd bet sparks too.

I hadn't seen the thread until now, but I'd hazard a guess that the MoT man does well at Christmas. None that I know would fall for underseal.

Measure it and go to https://simplybearings.co.uk/shop/Bearings/c3/index.html I generally choose anything Swedish or Japanese.

I think I'd be trying the usual suspects then. Underneath and check for play in the UJs!

If it's the clicking noise is what you mean that sounds more road speed related than engine speed?