Hi all. I am replacing the drain, faucet, and handles in my old 1940's bath/shower combo. There is a small linen cabinet with an access panel right behind the bathtub.

One plumber told me that he would need to rip out the wall inside the linen cab. in order the replace the old 3/4" shower riser, since new fixtures are 1/2". Another plumber told me that he will not need to replace the shower riser because there are converters for this type of situation.

Does anyone know which is right, and what I should do? I have pics if that would help, just let me know. Any thoughts are much appreciated!