Ive asked this before a few years ago (and received an answer to leave it to the pros), but in case there is new experience around does anyone have experience in stripping a round action (e.g. Dickson/MacNaughton)? What is needed is a clamp for taking the pressure of the fearsome curved springs, and putting it back on again, but Ive never seen such an item.

You stick a screwdriver in the notch in the rear of the spring, and push it forward and up. It'll pop right out.
When replacing it, just push it down and forward, to snap the spring into place.
I grab the front of the trigger plate in the vise to hold it steady.

I have no idea what is so "fearsome" about them. Ignorant gun writers, I suppose.

There is a good and sound reason to be very wary about those beautiful Scottish offerings to the gun world, on this side of the pond though things may be different on your side. You break one of those curved mysteries of a main spring in a vintage round action your Bank Account will understand the meaning of "Fearsome" in no uncertain terms, in fact I will go as far as nearly complete emptying if you need to have one made and fitted to your gun.

Yes, I have made several mainsprings over the years for round actions - and not from me breaking any of them. Actually as springs go, they're a pretty straight forward job. Nothing mysterious at all.

Thanks a lot Mike. I will see if you can make me one if it all goes wrong!

If it all goes wrong I will make you one , no problem at all .