The more I look at these original parts the more I'm convinced that they have yellowed over the years. Especially the lens. You can see that the part of the lens that wasn't exposed to the sun because it was tucked into the assembly is considerably lighter. Here's some more pics just for the "fun" of it. Took a few with the lens and assy laying on a white envelope to help show the color difference compared to white.
All of this because I wasn't careful when removing the original lens. Went at it from the side instead of the top or bottom.
Note to self: "Be careful dummy!"