The “hammered” effect is just rectangle dimples. My guess is after the hinges were punched out, they were put in upside down when the barrel stage was being done.

Easy to install and worked great. Access to youtube install instructions video is very helpful. Pretty simple to install.

Comes with two hinges and an instruction booklet. Slightly off, but enough to keep your lid from closing all the way. Experimented with 4 other sets of gas struts/soft close rods with no luck.