Rearming Iron Duke with larger guns

Could HMS Iron Duke have been rearmed with 15-inch guns for service against Scharnhorst?

Possibly, but it would require major barbette work; a 14-inch conversion was the more plausible option.

Iron Duke could conceivably receive 15-inch guns and serve as a counter to Scharnhorst, but the conversion would demand substantial alteration. The existing barbette dimensions make the larger weapon a difficult fit rather than a straightforward turret exchange. A 14-inch rearmament appears more technically plausible. It would still improve striking power while requiring less intrusive work.