Internal Wire Upgrade for SME V

No, you don't have to. It's not necessary, you'd better upgrade a cartridge. Silver is not better than Copper even if you want to believe it is better. 

Thank you Chakster! Keegiam, unless a wire is broken leave well enough alone. The SME is a fine tonearm. All tonearms are relatively delicate devices. It is not hard to injure a bearing. If that happens you have a Christmas tree ornament. 

Chakster and mijostyn, the wiring would be replaced by the service expert as part of his installation of my new AT cartridge.  I haven't seen anything in the forums suggesting that a professional has ruined a tonearm during a service like this.
Do you still recommend against replacing the internal wiring?  I have seen numerous comments that the wiring used in the early SME V's was one of its few weaknesses.

All my experience with DIY wire is it always seems like a good deal but never even comes close to professionally made. I would either skip it or go with Origin Live which at least I can be certain will sound amazing. 

Hearsay is dangerous in the audio world. The "service expert" is just as likely to damage the arm as anybody. Accidents happen. 
The SME V has been around for a long time and there are many on the used market. Just like cars audio hobbiests love to hop things up just so they can brag about how special their SME is. 
The only thing that changing your wiring will do is give you bragging rights. In my book that is just not worth the risk. And, why are you not installing your own cartridge? Bouncing your turntable and arm around town is not a good thing to do. Once you have a turntable set up you leave it where it is. If you know how a screw driver works you can change cartridges. The money you save on service will pay for the few tools you need. With the stylus guard on it is very hard to damage the cartridge.