It doesn't make a difference to me, although others may feel differently. I would prefer it to be updated and if it kept the OEM exterior appearance, all the better.
My '71 Z is currently a collection of OEM, installed at the factory in Japan, and replacement parts installed in five or six states. So, no worries. I can't imagine a "purist" pulling a radio and opening it to see if it had original circuitry. That kind of fanatic would probably also "sniff-check" the air in the original spare to see if it had been replaced.
After dealing with Porsche cars and car shows for 40 years, I know there are Porsche owners and show judges who are probably that fanatical. But, I haven't run across the equivalent in the "Z" community.
Dennis