Spmeone had installed the "my favorite Martian" antenna on my coach. It was not OE. OE was a skyliner on mine, who knows if the one you have was OE on your coach.
The antenna replacement is straighforward, but you have to be prepared to do some dissassembly.
Before you order a Batwing (they do work well) You need to be sure you will have the room for it to store flat on the roof. If the room is there then it is a matter of removing the old one, and installing the new. The instructions are well written, just trust the measurements that they tell you to use. If the wiring to your antenna is good then it is really easy. The antenna downlead goes to the plate, the feed from the coach attaches at the baseplate too, and the booster plate installs inside. If the downlead is bad then you have to remove celing panels
Not fun, but can be done in a weekend.