There has never been an ACF Center Flow 2-bay covered hopper made for G gauge/G scale.
The 50' High-Cube Box Car could be produced in 1/32nd scale.
They could make a modern, Post-1970 Thrall Car/Pullman-Standard/Trinity Railcar Gondola for 1/64th, 1/48th, 1/32nd all at the same time.
Andrew