I would do something that would have been from his dad's era. Roy Weatherby was a hero to many back in the day, and most of our "magnumitis" today comes from seeds ol' Roy planted back in the 1940s.
I'd get a nice, composite stock, a Jewel trigger, a Lilja barrel 26" long and have the rig chambered for the original...and ol' Roy's favorite...the .270 Wby Mag. Not a finer long-range deer/elk round exits.....!!!