... all the firewood is safely stowed away.

As a special "bonus" I deconstructed the large palletised crate it all came in and sawed that up for kindling.
3 full sacks of kindling that I don't have to buy.

Went out for a quick blast in the mini as a reward to myself.
That oil leak has not shown itself yet. I have no idea how/why swapping plugs 2 & 3 would maybe resolve it.
Or, there has been insufficient "blasting around" to get the leak to occur at the rocker-box gasket.
I have a big wad of kitchen-towel tightly folded and wedged between the top-side of the plug and the plug well wall and it is still clean and pristine. Very odd.