I'm not a collector, but a Bitcointalk coin somehow sounds very attractive. Until now I haven't even joined any of the many giveaways because I don't want to dox myself, but I might have to reconsider for this anniversary edition.
Id also be willing to offer my engraving services, but am not sure that private keys known by an individual would be a great idea.
BIP38 can limit the risk, if only the receiver knows the password and the encrypted key gets engraved.