MA 40 is an old rim, so I suppose the hubs are same vintage along with the spokes. Breakage inside the nipple is a sure sign of spoke fatigue, especially if it is doing it on the front wheel!
Assuming the hubs are good quality and the spoke holes are still round and tight, I would re-lace wheels with DT Champion 2.0. Reminder: check the roundness and true of the rims after dis-assembly If they are not round or true you will have to settle for uneven spoke tensions and a lot of extra work.