well as long as Congress doesn't let him keep it, hopefully
BILLION dollars stolen from nuclear missile maintenance program to refurbish it
Korean Airlines has a handful of 747-8 in active operation but they're making moves to retire them especially post Asiana merger.
Air China also operates a handful of 747-8 and 747-400 on both international and domestic routes.
FlightsFrom is a great resource to find routes for specific aircraft: https://www.flightsfrom.com/explorer/FRA?aircrafts=747 https://www.flightsfrom.com/explorer/ICN?aircrafts=747
Great seat number though.
I only ever flew on the upper deck in coach configuration, and the last time I did that was about twenty five years ago on SAA. It wasn't anything special, but it was a little quieter.
And both B747 and A380 fly much calmer than the smaller, lighter widebodies, which is equally nice for passengers on all classes.
There's still a few of these in passenger service, so you can easily get it done if it's important to you.
Otherwise, you'll need to figure out how to get on a cargo flight.