Essentially it's such low ampage that anything would do, but I'd like it to be compliant.I've been reading the code, and I'm making one alteration to make the installation an extra half inch from the roof deck (they were going to be 1.5" from deck, now 2"), but I can't find the exact codes for the wiring type.I have found some CL rated speaker wire in 18gauge, rated for 150v.

That 70's stone is about 4 inches thick im guessing.

I would not go beyond a couple of inches in width.

The clog itself was about 40 feet out in the 4 inch line.

You will need to dig a 6 inch trench around your entire perimeter of your building.

You can spin it left or spin it right or maybe even move it an inch or two (a hassle) but design around it.  

I always heard that fire damage deeper than 1/8 inch whole piece of lumber needs replaced.

Can get it in 30, 36, and 42 inch uppers which is great.  

Sanding and refinishing what's there, or cutting some 1/4 inch plywood to fit and finishing that might work.

It was trespassers.Better security -- yeah, too bad booby traps are illegal.Anyway, secured them tonight with 4 inch counter sunk screws and wood that was laying around.