The worst non-"restoration" that my eyes so far did meet, was just posted in this forum, in the Imman. Meffert thread.

Atrocious dark black "cold blueing" over sanded metal. Gross contrasts. Proud metal vis-a-vis over-sanded wood with round edges. Creepy, but an excellent example of "how not too".

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=671758#Post671758