with your Tuscany, if you have an articulating swivel arm, you may find that the connections come thru/from the interior wall/behind the fireplace.
if it's a flat mount, it should be mounting similar/same as the majority of the other outside TVs that most of the rest of us have, which is a screw-mounted frame, which then simply lift up and off the main bracket when the screws are removed.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada.... formerly Georgia, then NorthCarolina, now Alabama : )