Well, we never had any Mark 45 from Hasbro or Diamond Select.
But we had this figure: A Mark 45 painted as a Mark 46 on eBay and Aliexpress for sometime.
A fellow South Korean collector told me the story about this figure:
ZD Toys made this figure to be the first release of their line of Marvel Figures but put this idea down and went for a full "Captain America: Civil War" wave in 2016 with the Mark 46 and all the other characters. They had the Mark 45 mold and didn't want to pay the fees to make a "Age Of Ultron Mark 45" so they painted this figure as Mark 46 and marketed it as a "2nd Mark 46" - is this story true? I don't know. But at least is interesting.

I bought this figure only to repaint it the right way, it has ALL the sculpt right from the Mark 45 and have good articulation (and a LED Arc Reactor). I've painted it all with Acrylic paint and put a Glossy varnish to make it shiny (Like the new ZD Toys Figures) and metallic-ish.

It came with 4 pairs of hands and I've used some bootleg Mark 45 Revoltech hands to use their repulsor blast effects.