To zap or not to zap

I have an 18 year old Xweetok that I was recently able to paint disco. His petpet is also 18 years old but...he's a Ditsy. I love him, he was probably the only thing I could afford At the time, but it kills me that he doesn't match. My dream petpet would be a disco Tasu but there is no way I could unpair such an old petpet. My question is...would you risk zapping him. Knowing that his disintegration would be absolutely devastating...what would you do? Should I just love my mismatched duo? Should I risk the zap?