I’m not sure what makes you think this is based upon another font. Logo designs are not necessarily made by modifying fonts — I am not a logo designer, but I feel pretty confident that this is a true statement.

If you are trying to find a starting font to modify for a similar result, maybe Souvenir Italic in a heavy weight would be a bit similar. At least the ‘s’ would be similar. Overlay the ‘u’ and ‘n’, remove the ‘i’-dot, and at quick glance you might be fooled, if you weren’t comparing them side-by-side.

How about Cooper?

I think they may have used ITC Clearface Black Italic as a basis.
All the elements are there, especially the (difficult to construct) “s”.