Originally Posted by Ant-manic
Spymaster should infiltrate his circle of friends; meaning masquerading as Pepper, Happy, or Rhodey.
p.s. Terrence Stamp should play Justin Hammer senior.
If he weren't Magneto, Ian McKellan could've worked.
Another possibility is Jesper Christensen (Mr White in Casino Royale). I once saw a picture of him with white hair (I can't find it on the internet now) which he had for a role (don't know which one) and it made him look much older. He looked very like Justin Hammer in it.