I've got this nasty feeling that in a few years time, when Reliants have attained their rightful place as icons of the car building art, people are going to say What a crying shame there's none left on the road -those bloody Monkeys cut 'em all up.
And so the madness begins once more. Will they never learn!
Photograph everything Si, to show us all & also for your own reference when you forget how the damn thing goes back together. You'd be suprised how often we get told how useful some tiny snippet of information in a build thread has been to another reader. Your tinkering may well be directly responsible for inspiring the next Monkey to have a go.
I'd suggest keeping things like radiator, cables, (you could do the same as Taz & run the speedo off the gearbox like the original car, but if not you can cut the end fitting off & use it to blank the drive unit on the gearbox), handbrake lever & mount, fuse box, dashboard gauges, exhaust -even silly stuff like number plate lights or full rear lights might come in handy.
Take your time, be careful, (don't want anybody needing adapted controls cos they've chopped a finger off with an angle grinder), but above all, have fun! Remember, if you're not happy with something, you can always do it again.
Good luck!