Clearance question

Are clearances measured up to the height of a stove or do you need to be at the "manufacturers suggested" clearance for a complete wall?
Here is my scenario.....MArk1 is 32 inches tall. Will sit directly in front of my fireplace which is, oddly enough, made of brick and not combustible.
At 37 and a half inches up my wood mantle sticks out 1 1/8 inch. At 42 inches up it goes out to 8 inches.
I plan on using a heat shield, which I understand reduces clearance by 50% (which, for the Mark 1 would take it from 24 to 12 inches).
Do I need to be 12 inches out from the outermost portion of the wall (edge of mantle), regardless of the height of that point.
Also, is the clearance measured directly behind (or to the sides) by the width of the unit? Unit is 20 inches wide. Would I need a wider heat shield?
Not drinking, just having a hard time trying to put my question into words.

You have three choices, remove the mantle, move the stove out or make a double walled heat shield. The safest way is to eliminate the mantle.
You only have 5-10 inches of clearance from the mantle to the stove vertically? Can you move the stove out 10-12 inches? This will give you enough clearance with a single wall shield. You could see if a double wall shield passes muster with the local inspector. A double wall shield with 1 inch air gap each layer will usually get you a 6-10 inch clearance. Still too close as the stove is only 5 inches now.
Do you have any pictures of this install?

I haven't done an install yet. I want to be sure of my options and safety factors before I do and welcome the input of seasoned coal people. Right now I'm planning to go with the single heat shield at 12 inches. Just wondering if the clearance is only up to the height of the top of the unit or does it go beyond that up to a certain point.
My local building inspectors office says to go by the manufacturers clearances. This seems to be SOP from what I can gather.
Does Harman suggest the use of a heat shield or heat shields. If I can do a double wall and bring it in closer I would definitely consider that.
I would think that there would be some point vertically where the heat is dispersed enough that it would not be an issue.
Once again, all input is appreciated.

The clearance is from any point on the stove.
Use a string 12" long if it touches wood or any combustible it is too close.
Heat shields directly attached to the stove are about 1 inch wider than the actual stove.
Attached to the wall would be wider. The extra width is necessary until you meet the unshielded distance, use a 24 inch string.
I can provide you picture of my VC heat shield which is attached to the stove if you need some ideas.