Ok, Macharius' education on the Horus Heresy was apparently extensive. Here's what that roll gets you: He identifies the helmet as MkVII. It could still be quite old, since this was one of the final armour versions developed during the Horus Heresy itself, but it was developed on Mars, during the final stages of the Heresy, and shipped to Terra before Mars was temporarily captured by the Traitor legions. This armour marked the first time that any legion apart from the Emperor's Children bore the Imperial Aquila, and was also known as Imperator or Aquila armour as a result. Though the designs have changed little since the days of the Heresy, this particular item doesn't look that old - you've got a pretty good idea of the appearance of things from that era by now, for obvious reasons, and this one looks like a more contemporary example of the armour. It is unlikely it belonged to a member of a traitor legion. Unfortunately, Blue is a common colour for space marines given the Ultramarines and their many successors, so placing this helmet could be difficult. The main clue is the head crest, which suggests an aquatic or dragon-themed chapter, or one to whom those motifs are significant. A Salamanders successor would be an obvious pick, but there aren't many examples of those going well, and no known Salamanders successor uses blue as a primary colour.

Unfortunately, this is where SL: Legends runs out. SL: Heraldry is your best bet if you want to know more, but CL: Imperium might get you something if you roll especially well.

For Anika: The statue is likely of xenos manufacture, but it would be challenging to say exactly which one. The figure doesn't match any species Anika recognises.