jqp - I think those trim pieces are called "end caps".
Below is one of the inside pieces.
Josh - Good to know, I was unaware more of us had the new title. I was looking at other members with higher post counts than I, than didn't have it.
But I agree with George, there are other (worse) names that could be given to us.
Jonh - Thanks but, I've already sent the finer details of the project to your "Significant Other".
Last I heard, the supplies should be delivered to your place in the next couple days.
Tom - Thank you VERY much for the kind words!
Pictures of your place would be great, when you're able.