Just a quick post for today in this topic.
I gathered a handful of theory of how the hypothetical "corona latina" looked like. Most of them operates on the basis that there were 12 apostle icons originally. Some questions if those were on a crown at all before they were placed on the Holy Crown. Since today it seems sure it was never a crown in the first place and back in the day they recycled other items to create a new one it could have happened. But we have no actual evidence, so the icons may or may not were made specifically for the crown.
And since we're talking about the icons, in the previous posts about the apostles ( >>/27050/ and >>/27052/ ), look at their eyes, they all squinting. While the figures of the rim have directional looks, they look toward the front or stare back straight to anyone who looks at them (typically the two emperors) these ones on the top aren't. This squinting look might imply they doesn't watch this material world around them, but they look to the "other side", into heaven.
I won't post the head relic holder again, you can find it here >>/26899/
I think right now this is the post popular solution to a most likely nonexistent problem.