Question on triple blade chainring

[Guest]

The more expensive chainrings has milled out pickup teeth. The two larger chainrings on my tandem has little studs riveted to the blade. Each has four holes and I pressume there were four riveted studs in each hole. The large ring has one missing and the middle ring has three missing with the third riveted stud half loose. Do I have to buy new chainrings or can these be repaired?????

Thanx in advance

Keep those wheels spinning!!!!!

Big H