Finally, some progress.

I've started by putting some lockwire through the four bolts for the cam-follower locating plates, although this isn't actual safetying, in aviation terms. That, I must confess, rubs me the wrong way, but unfortunately because of the extremely narrow gap between the bolts, there simply isn't enough room for anything but the half-assed job you see below (although, shockingly, I have seen much worse):

At least you can see the nice cross-hatch finish on the bore.
Now, if you want to understand what proper lockwire is all about, do yourselves a favour and have a shufti here: Jet Tech: Lockwire  (I know, it's awesome).

Then I fitted the piston rings: always pay close attention to any markings (usually dots, or the word 'top') and/or any bevels on the rings, and always refer to the manufacturer's instructions. In this case it was very easy, and the rings were clearly and conveniently packaged according to their location on the piston. Naturally, you should stagger the gaps as much and as evenly as possible to ensure optimal oil retention and prevent blowing smoke. That would be very annoying.
Look, in general, just read the damn instructions and do what the manufacturer says. When you start making your own parts, then you can do whatever you want, but until then, that little instructions sheet is smarter than you.

I'm using a really crappy rings compressor to get the pistons into the bores, on the bench - as opposed to fitting the pistons on the conrods, and then trying to fit the cylinder block on free-flopping pistons whilst trying not to snap the rings. To me, at least on paper, this sounds like a neater approach, but I can always do it the other way if I don't like it, we'll see. Anyway, like I said, this is a really low-quality tool that I bought online for very little money. I might end up using my fingernails instead.