Here is my custom made, Pre-Heresy, Mark 1 Terminator Squad. Based closely on the original concept art by Jes Goodwin from 1988.
I have only armed them with the original proto- Mars Pattern Stormbolters and Power Glove that they were designed with. The Sargent with Power Sword is a one-off conversion.
I think the background of the armor aught to be something about first battlefield adaptations from Mars for use in the Reunification Wars, later called the Great Crusade.