Wait, what about... [url=http://fallout.wikia.com/wiki/Winterized_T-51b_power_armor]this?[/url] There [i]were[/i] T-51bs in Anchorage, standard issue in fact, if one was a member of the Mechanized Cavalry Regiment (otherwise, you wouldn't have power armor at all).

I really don't see the harm in letting him have one. In fact, it actually makes less sense to give him a T-45d suit...

After the Reclamation, the Army brought most of their combat troops back down into the U.S. (which at that point had annexed Canada), including their Mechanized Cavalry. If he was a soldier who would have access to power armor at all, it would be T-51b.