Britain did not need a foreign 4.7-inch design

Did British 4.7-inch gun development depend on design ideas borrowed from other countries?

Not to any important degree in this case; Britain had several very large arms manufacturers and enough domestic expertise to develop the weapon itself.

Some foreign influence may be visible in the later 50-calibre branch, but the British programme did not require overseas design help. Firms such as Vickers-Armstrong operated inside an unusually large domestic arms sector. Britain possessed several manufacturers capable of designing and producing complex naval weapons. The missed opportunity arose from programme and funding priorities rather than a lack of technical sovereignty.