Just when I thought I was finished with this saga...
Everything went back together and I didn't have any worrying nuts/bolts/washers left over. I started her up and let her idle for fifteen minutes to heat up and make sure nothing went pop. Not only did nothing go pop, but nothing heated up with the temp gauge staying almost unmoved. A quick inspection of the thermostat showed that there was nothing inside it - no moving parts at all. In fact all that was left was the top cap to keep the water in.
One new thermostat later and another fifteen minutes idling gave me a warm engine. Good. However, a quick test drive generated a small oil leak from the sump. Surprising that there isn't a gasket here, does anyone know why? Lots of silicon and 24 hours of curing later and all looks good.
Apart from the battery light on the dash isn't on and the engine isn't running as smooth. A bit of research throws up that if the battery light bulb goes then the alternator can't charge the battery (a new 1000CCA battery). Sadly the bulb isn't blown, it's the alternator which is now needs attention. Hopefully its just some new brushes...
It rhymes with clucking bell.