another shot of the backing plate

You are obviously doing a Class A+ refurbishment of your Z based on the photos you posted. That is consistent with top-notch quality of the headlite harnesses you made and sold to some of us. The harness is a 3X improvement in visibility by the way.

Any problem with those SST brake lines (Earl's)? I bought set but have not installed yet. I was concerned about retention to the right-angle mount bracket using the stock, spring type, u-clip due to dimensional differances

A little wiggling and banging and they go right on.