Shelley Andante Script  Suggested by donshottype 

The thin white monoline script is actually neon tubes bent to a custom pattern.
The grey background is a formal script with ball terminals.
It looks like a thickened version of Shelley Andante Script, or a very similar script.

Compare the thick grey letters to Shelley Andante Script with _M_ reduced to 90%, all letters thickened by a parallel line and sloped left 8 degrees:



If the sign-maker did some tweeking, such as rounding the ball terminal on _M_, then this thick version of Shelley Andante Script would have been fairly close to the final design.