For future reference, and in no way to downgrade your relative, but most vets know as much about chinchillas as I know about rocket science, especially the "experienced" ones. There are some who actually know what they are talking about, but I never take what my vet says as the gospel. I turn to people who actually own, raise, and care for chins for verification.
As far as a vet visit, there is no need unless something is wrong with him. Well checks are pretty much laughable at a vet's office, other than to give the vet money. What can they tell you, especially with a kit?
Yes, he has fur, excellent.
Yes, his teeth are orange/yellow, again, excellent.
Four paws - check.
Two ears - check.
Do you get my point? Unless he has an obvious health issue like pneumonia, an ear infection, fungus, a heart murmur, etc., then there is no point to a vet visit.
I also just want to point out, that we all knew you would take him home at the original date decided. What we were trying to do, from actual experence with owning and breeding chins, was let you know that it isn't the best idea and why. Ultimately the decision is yours, and of course we will still be here to help when things go wrong. We would never abandon a chin in need.