Mantel questions

As we mentioned previously, here's some of our foot-powered liberation handiwork. This used to be a fireplace as you can see. We're hoping to take the mantel from the top floor front and bring it down here (back of parlor), which will be nice to have in the kitchen. The mantel will be a nice counterpoint to the modern kitchen design that our architect is formulating. We're not sure why the mantels in several of the rooms of the house are gone. It is conceivable that at some point the fireplaces were too much to maintain and thus closed up, which could be the reason. Though why would you remove them? Another view is that there was a shortage of money and the mantels we sold. The final question is, for the mantels which remain, why would you paint them?