My original 1984 Gibson RB-250 clamshell tailpiece is still in great shape. Would I get any sound benefit from changing it out? If so what do you recommend? Is it worth changing out just to make string changes easier?
It's a simple, reversible experiment. The clamshells, especially that vintage, are among the hardest tailpieces to change strings on. So you'll gain ease of use if nothing else. The tone could get better or worse, but keep in mind that you'll have to go through a bunch of setup experiments to find the optimum setting for the new tailpiece, and a new tailpiece may affect the best setting for head tension and other variables.
If you decide you don't like the result, you can put the clamshell back on, and either keep the replacement tailpiece for future experiments or sell it on the Hangout. You are doing nothing you can't undo. Just keep the clamshell so you can make the banjo fully original at some future date if you want.
There is nothing sacred about a 1984 RB250. Although the clamshell tailpieces look cool, the clamshell was known to "rattle" somewhat on the originals. The fix was to put a piece of foam under the shell. They were a bugger to change strings on but, how often do you have to change strings? Unless you break one while playing, string changes are usually done at home when you can take your time changing them.
The Kershner tailpiece is a good design. Properly made it is strong & facilitaes easy string changes. And it doesen't look bad either. Were it me, I wouldn't hesitate swapping it out. If for no other reason, you'll learn a little about banjo setup from the experience.