I have a straight lug riveted bracelet dating from 4/54 which has an issue with the middle link at one end. Secure at one end but missing whatever kept it in place the other end. Being riveted is this fixable otherwise do you believe it would be safe to wear as is. Link has some marks on it so may have been knocked and spring action works but is stiff. Hoping I have explained the issue enough for someone to suggest a course of action