Bonnie , I picked up a stainless steel lockset at the HD, and put it on the FS ... Seems to hold up well being outside and the door knob feels (to me ) more “Natural" than a lever type camper/RV lock .
If you choose to go this route , I’d highly suggest buying /borrowing , a hole saw set specifically made for drilling out the door holes for the knob. Makes it EASY to do then ...