I picked up a +3 Major Fire Lore Scepter of Greater Spell Pen III from the Inspired Quarter last night that gives me +9% crit and +0.50 dmg multiplier on fire spells. I also have maxed out the Spell Critical Chance: Fire/Cold and Spell Critical Multiplier: Fire/Cold Enhancement lines so my question is do they stack? Would I get a +18% crit chance with a total of 4.25 dmg multiplier when you add the the multipliers up from the two enhancement lines and the Scepter? On top of that I have a Superior Combustion Scepter that gives me +50% dmg on all level 7 and below fire spells. Does that damage get tacked on as well?

I am going to do some testing to see what I come up with but I'm wondering someone else has already figured this out.

Thanks in advance for your help!