Went out for a hike here in the desert in San Diego and found this off the trail unearthed by a heavy rain. It looks to be a Colt 1851 Navy, but I’m not very knowledgeable on this subject. I respectfully ask for some info from you guys, I would really appreciate it. Serial number D61755 4 hallmarks 2 are symbols and the others are “PN” and “BC”. Thanks in advance.