Not a replacement for damblock, but an addition.
Body tokens [ARMOR_HARD], [ARMOR_SOFT], [ARMOR_NONE], and [ARMORLEVEL:n].
The first two would protect the body part to which they're attached until they're broken or worse, at which point the protection would cease. Hard armour (shells, bony frills, etc.) would protect against piercing and slashing but less against bludgeoning attacks, and soft armour (thick skin, thick fur, etc.) would soak away hammer damage but be weak against a strong arm and a sharp sword. Multiple armour parts attached to the same body part would provide extra protection through chance. For instance, a dwarf facing a creature with one mangled upper back plate and one unbroken one would have a 50% chance of striking the unbroken plate. [ARMOR_NONE] would be available if you wanted to have the opportunity to pull off a dramatic lucky shot without having to force your way through a layer of armour.
Protection could take the form of a modifiable number from which the material strength of the weapon is deducted. So a creature with [ARMORLEVEL:200] and soft armour would reduce damage from a plain bone bolt by 150% (so, zero damage), damage from a plain steel bolt by 67%, and a masterwork iron bolt or anything better would go right through. If it had hard armour anywhere, the masterwork iron bolt wouldn't be enough to bypass the armour completely. A masterwork iron hammer, on the other hand...
I know basic subtraction isn't good enough given the current material damage ranges in DF, but it's just a quick start (armour vs. ammo in particular would likely be near-impossible to balance with vanilla DF as it is). The damage reduction should probably be applied after the attacker's Strength is taken into account and before most other things, but that's really Toady's area.
Having some of the armour level carry over to the creature's hide would be nice too, since kitten leather is currently just as protective as elephant leather.