I decided to stick with manual data-entry rather than scanning & OCRing it (which grahamb had suggested), partly coz scanning everything on a flatbed scanner that lives under my desk wouldn't be terribly much better for my back than typing stuff in ;) Partly coz I haven't got the scanner set up yet (bought a new all-in-one printer just before Christmas when I saw one on offer, to do the Christmas card labels, only bothered to set up the printer so far). And so I'd have to figure that out (probably just works in Win7 tho), and then sort out OCRing it, and then check it handled the 4 different handwriting styles (and the mess that sometimes was made of the data entry). And that all seemed like a lot more work than just typing numbers in (and if I do it a little at a time, it'll not be that bad). And so I typed up the rest of 1986 yesterday :)
More work on the script, too - got it to get rid of the linebreaks (thanks marnanel :) ), got it to handle 0 and empty fields differently (thanks jarel, who also figured out why some of the empty fields were empty & some were undefined :) ). And got it to draw some proof of concept Max/Min graphs, of which this is a representative sample:
Obvious flaws - needs scale marking, it's too small, colour choice sucks. But hey, it's a graph! ;) J had to help me figure out some stuff, and I really seriously need to tidy up & abstract the code that draws it coz it's full of numbers (which I found easier to follow at the time but later it's going to be an incomprehensible mess and changing anything is tedious). It's progress though and once I figure out one set of graphs there's several subsets of the data that I can represent with not much more work.