Thank you for your comments, gents.
El Freddo - I'll certainly be checking that pump thoroughly, I have a Subaru Sambar service manual which I use for engine work- it is the same engine as far as the major components are concerned. I have all the new seals too.
General disorder- That article is really useful, thank you; I was concerned about the honing part, especially as it would likely be done inaccurately with a hand drill as I have seen and read all over the internet. Doesn't seem the most professional method for these Japanese motors.... it scares me a bit!
Additionally, the bores actually look really good, and I was secretly hoping that a good reason NOT to hone the bores would crop up. And it is totally intuitive that a well 'finished' shiny not worn cylinder is what is needed.
Four bores like this; excuse the shop-rag residues:
There are even traces of the factory honing on all bores:
The pistons show a light polishing on the pin sides of the skirt, but no 'rubbing'.
I am installing brand new Subaru rings, though the originals look quite good too. (I snapped one stupidly while giving the piston a preliminary clean, damn they're fragile) . Something to clean the grooves with!
I am waiting for some parts, which gives me time to check and clean, and I'll post my progress and countless questions.
Thanks again!