Short answer is still no for me - but I think I have a plan.
Below is a picture of our culprit - the ebrake lever on a LS1 backing plate. In this shot, picture this backing plate mounted to your left rear wheel. The lever in the situation would be set up for the cable to 'pull' forward towards the front of the car, like our stock setup.
The reason we have a clearance issue - at least on the narrow 12 bolts is due to the proximity of the LCA mount to the housing flange. The narrow rears have 1/2" less clearance per side between these two points. This is taken from in front of the rear wheel. not the best shot, but my battery died - sorry.
Picture that lever needing to fit in that gap - kind of tight when you set up for the cable to 'pull' forward.
Many have suggested flipping the plates to the opposite sides. Look above at the backing plate and picture that on the right rear wheel. Due to the rearward angle of the LCA mount, the clearance issue clears up. The problem then is that youu need to pull that lever to the rear of the car. Doable, but you need a long cable and you'll have to bend it 180*. Not the best.
So here's my plan - that lever comes out, so it's relatively easy to modify. After fittiing the backing plate with the correct size shims (somewhere between 1/16"-1/4"), I'll measure and cut a section out out of the lever, maybe even reposition it forward a bit and weld it back together - this would maintain the 'hook' on the end for the cable.
In this shot - picture the section between the scribe line and the end of the grime cut out and welded back together.
I might lose some leverage - but I really don't think it will be enough to hurt with a foot operated pedal. And the more shim I need, the less I need to cut out.
I still need some parts, and life's getting in the way again - I'm a month away from actually starting - So to get back to the original question, no I haven't actually got the brakes to work yet - but I think I can! I'll put a pictorial together when I do it....