Paul - thanks for all your help with the Stanley #4.
I ended up buying a new iron and iron cap (the original was badly ground, had a rounded corner and only met the plane iron for about a half of its length) for the #4, ground off a lot of paint from the frog and set it up, and it now works very nicely.
I picked up a #3 at a boot sale for a fiver, cleaned it up, put in a new blade, having found that our local ironmonger has (had) a small supply of age-old Stanley replacements, and that works very nicely, too. As does the #71 in its original box, all cutters present but only one ever used, in immaculate condition for £25. Good boot sale. I might go to another one.
Now I'm after a hand brace and original auger bits, having just missed a nice one on eBay.
Does this tendency make me a neanderthal or a galoot, or is there a difference?