There is a distinction between Londonderry's products (generally made for them by Optimum Brasses in the UK, though they have other manufacturer's products) and Horton's and Ball and Ball's.
Londonderry's are made -completely- like the originals were, including the cast posts & nuts, or cotter pins, depending on the style/period. Horton and Ball&Ball, probably for reasons of cost, supply modern cut-thread posts and hex nuts though you could substitute out the hex nuts for square ones.
In other words, Horton's and Ball&Ball's products will be fairly convincing from the exterior of a piece, but -instantly- identifiable as a modern reproduction when a drawer is opened. To many, that doesn't matter. To some, it does.