Does OH spec (Fury) stack with 1H spec (Prot) ?

[Dr. Doom]

Hypothetical build to illustrate what I mean:
http://db.vanillagaming.org/?talent#LZVVzux0oZVitc0hzV


Not going to argue that it's great or optimal or anything, I'm just curious about it. Does 1H spec affect offhand dmg as well as main hand? If so, does it stack multiplicatively? x*1.10*1.25 ?

Just today's pointless curiosity.

[Mugo]

Yes they do. But you be needing tones of +hit items on yer hands.

[Dr. Doom]

Yes they do. But you be needing tones of +hit items on yer hands.

Alright.

Another question if you don't mind.

Is the 25% dmg increase from the OH spec applied over the base value of the weapon (meaning the OH would end up doing 75% of weapon dmg, due to -50% penalty + 25% bonus), or over the reduced based damage (25% of the reduced 50% value, meaning 62.5% of weapon dmg) ?

[Mugo]

Both apply to base. Meaning it's 62.5% of weapon damage.