Well congrats on the great Christmas present. What is its condition as to metal & wood finish? Its not hard at all to care for a old Winchester. Just wipe the metal down with a light oil on a rag or a lot of guys use Old West Snake oil which you put over the whole gun or others use a Renaissance and Conservator’s wax.  If the gun is a high condition with a case colored receiver then you want to keep it out of direct sunlight as that can fade the color also don’t use anything that has lemon oil in it on case colors.

Are you going to be shooting the gun? if your not then there is no need to check it out but if you are then you can have someone check it out. I don’t know anyone in the St. Louis area but most gunsmiths should be able to inspect a gun for normal issues. The only problems special to the 73’s is the toggle links which can crack at the hinge which comes from removing stuck shells with the lever. Just don’t let them talk you into refinishing it if its in poor condition, they can’t refinish a old Winchester, they send to the guy they send all their shotguns to. It take a special guy that knows how to make a Winchester look like it should which can cost many thousands.

Bob