Aristo FA Versions

I need to work on this section, will flesh out the versions of these locos. The two pictures below are courtesy of George Schreyer

I believe there are 4 versions of the FA, and 3 of the FB.

First version in "blue/gray" box, 2 lash screws on the motor blocks, holes in wheels, "hubcaps"?

Second version in black box versions,  2 lash screws

3rd version had motor block with no lash screws, ball bearing wheels

4th version (FA only) added the Aristo socket and changed to the new "prime mover" smoke unit.

The B unit never got the upgrade

At some point, both locos were lowered... I believe it was about the time of the 4th version.

 

Picture of "Blue box motor block

 

Picture of   "black box" motor block

 

Weather Underground PWS KCACARLS78