[Milsurplus] ? G.E. brushes

[Hue Miller]

Found these and would like to learn what they are for. Small cardboard boxes
and marked, after the GENERAL ELECTRIC name, 

2 Brush and Springs
5869390AB6
XN-111L193

same as above but with this number instead
5869390AB5

same as above but with this number instead
5861768AB1

4 Brushholder Caps
5898111AA5
XN-111L193

same as above but with this number instead
5898031AA2

They "look" about BC-375 "sized", that power range.
Tnx - Hue