I am not sure if this is pre or post 1980, but I think it is post. My father-in-law has a .45 colt revolver Model 25-5 with serial number N828xxx. I am trying to figure out when this gun was made and what else I need to know about it. I understand that some have over-sized barrels. Is that something I need to be concerned about, and if so, why? (Sorry, I am not particularly informed on these things). Thanks in advance to all of you who will give me your sage advice.