As with any new home, changing locks is a priority.  The previous owners had six kids and who knows how many grand kids. After forty plus years there is no telling how many keys are floating around. There were different options to consider but none were inexpensive since there are SEVEN exterior doors.  We could have had a locksmith re-key the locks but the hardware was obviously old and not really attractive. So we decided to purchase new.  We found some at a local hardware store that are modern and came as handle and deadbolt set. We didn’t want to have 7 different sets of keys so we went to several different stores to find as many as we could with the same keys. We found four that were the same, so we just had to re-key three. The hardware store re-keyed them for a minimal cost. In addition, the hardware store was having a “bag sale” so we got the lock sets at a discounted price which saved us quite a lot. Yes, we could have purchased online with all same keys, but that was more expensive and time was of essence.