The signature on the postal cover is undoubtedly bad in my opinion. A style I have seen many times with significant atypical traits.
The black signature against the lunar surface is reminiscent of the late 80s/early 90s "slapped on" signatures applied near the end of his signing days. Same thick black marker he sometimes used at the time. It has some odd traits, but some subtle positives as well. Given the quality of the image, it's impossible to ascertain key elements such as speed, flow, etc. I would reserve a firm opinion pending a comprehensive exam.