Not sure I had that. I had a superior Axe schematic and the only way to make its base damage slightly higher was by making it a master piece. Still damage isn't everything for a tank and the heal in kill isn't bad either.
But then again I only went for the best equip I could get on my main char, the other would get decent gear and it was more than enough for the game anyway. All the farming I did for better schematics was utterly pointless, even though I found a few things, that made my mage slightly stronger.
If you wanted the best one-hander for a tank, you would not use Caliban either. You'd craft a Griffon Mace with tank stats - the schematic is available from the T3 weapons vendor with the Short List perk. It has 17 metal damage slots [so 276 dps with Dragonbone], 10 metal utility (6/4), 4 offense, a haft and rune slot, so you end up with a 1H that 1) does more damage than Caliban, 2) has considerably higher constitution => higher melee defence, and 3) has masterwork that helps tanking either with survival or generating AOE threat. (10% chance of X seconds of Walking Fortress, +x Guard per hit, abilities cost X% less stamina, 10% chance of Shield Bash/Veilstrike/Chain Lightning on hit... whatever you've got access to, there are so many that work very well with a tank.)
Unique weapons and armour can be fun, and they often have interesting stat distributions, but in this game once you are past T1 nearly all of them have considerably worse stats than the things you can craft with easily accessible materials. (Exceptions exist. Longbow of the Griffon is an obvious example, the Staff of Tyrdda Bright-axe - due to how early it is available - is another. Sulevin is arguably a third.)
Of course, you don't need good items to actually complete the game, so there is no need as such to go craft items, but it seems a bit diminishing to the idea of the named unique items, that the rational thing for me to do from a character performance optimization viewpoint (though not necessarily from a fun viewpoint) is to sell the unique weapons and armour just like I sell all other weapons, armour, and "valuables" I find and ignore those in the shops (including those available from the Short List perk), in favour of buying the always available schematics (or better schematics with Short List) and use easily farmed materials to craft weapons and armour that are clearly superior to the uniques.