I have an 18kt cased Olympic chrono dating from 1940 with lugs that have short gold spigots to hold hollow spring bars. One of the spigots broke off and it was not an easy welding task for the specialist case repairer. The repair was made more difficult because the gold lugs were hollow to save gold in manufacture. The case repair was also a gamble because the case was quite thin and may have collapsed in the necessary heat. Any way it paid off and the guy did a ssplendid job and made a new spigot. Just have to be extremely careful changing a watch strap. I was told that similar spigots were not that uncommon. Drilling out the lug for a modern spring bar was not an option.