I had the armour rules sorted. They were working fine, and then it all went horribly wrong. I'd been handling armour as a set of modifiers to a model's Skill characteristics; so for example, a Shield costs you 1/2 a point of Move, 1 point of Concealment, but adds 2 points of Block. And that worked really well; in all the playtests heavily armoured models were slower, less nimble, and less sneaky, but much harder to wound. So melee combat was declared complete, and I moved on to ranged fighting. And realised I had a problem.
Melee combat is based on an opposed Skill test - Strike versus Block. Ranged fire though, is based on Ranged versus Nimblebness. And there's the problem; armour was adding points to Block. It gave no bonus against missiles! In fact, it was worse than that; heavy armour reduces Nimbleness - so a heavily armoured model was all but immune to a sword, but easy meat for an arrow.
So armour had to change; instead of boosting block, it now provides a negative modifier on the damage chart. So heavy armour won't stop you getting hit, but it can absorb some of the damage. Now that works for both ranged and melee; the only thing I'm still not too happy about is shields. It just feels to me that they should boost Block; they're designed for blocking, after all! So shields will probably be getting a rethink.