@linuxuser Yes, keep this thread on-topic. I suggest you create a separate thread for learning how to use G’MIC and related filter and commands. No need for it to be specifically about the richardson-lucy command. Call it something like “G’MIC fun with linuxuser”.
PS. As for processing, follow snibgo’s implicit advice and deal with the JPEG/camera-baked-in artifacts first before doing anything else. Otherwise, you are making the base image worse by enlarging and sharpening it further.