The model issue is worth noting. Older electronic scales often get a bit off over time. A balance beam scale, though, will remain good if it's been treated well. The Rock Chucker is unlikely to have changed significantly and an old one will be U.S. made rather than Chinese and may be tougher from more skilled avoidance of stress risers in making the casting. As long as it hasn't worn loose or been damaged it could actually be better than current new ones.
I don't think I've ever worn out a shell holder or other small part like that, so those should all be OK. Some priming tools have been improved on over the last 20 years (note that I don't know how long he actually had this stuff), so if you are interested in a specialty, like benchrest or service rifle match shooting, you may find a reason to switch. Loading trays are the same. Some newer powder measures have shown up, but the old standby drum and horizontal chamber types are unchanged. Not knowing what else he had, it's hard to say what might be obsolete. In the case of powders, it depends when he bought them.
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