Illustrated below is an example prototype U25B having vertically mounted stanchions for its railings like the Aristo replica. (Later “U boats” utilized side mounted stanchions similar to competitive EMD locos.)
Ken, to answer your question, yes it is possible to bend USA stanchion bottom ends straight and add a full length wire, but with risk of breaking off the bottoms - if not when forming but vulnerable when handling. The end bulkiness may be another issue to contend with when trying to fit within the U25B’s cat walk holes.
With the U25B having missing railings, compromise possibilities are presented in the illustration below.
If Gilbert has available RS3 plastic stanchions, they could be used with bendable electrical buss wire as described. In so doing, the cat walk detail may need to be filed flush and mounting hole size may be different.
If using USAT SD40-2 (or similar loco) taller stanchions, they can be shortened at its base and reformed / trimmed for vertical fitment without the issue of rebending (& possibly breaking) its right angle side mount tab.
-Ted