For a listing with 19 photos, and none of them frame shots.......ehhhhhhhh.
They tell you the frame is coated and seems solid (to them). Listing description....
2006 Jeep Wrangler LJ Unlimited. Comes with hard top, soft top, and Bimini top. After market bumpers, but also have the original that go with it. 10K Smitty built winch with wireless remote. Also, wireless phone charger, interior bed rug, and neoprene seat covers. Has poison spider rock sliders. Also comes with Rubicon rock sliders. Has rough country off road lights, fuel rims 33” BFG all terrain tires with 4:10 gears. Pictures show dirt and blemishes but there are none. Just reflections. We live on gravel so the underside is dirty. No rust! The jeep was undercoated before we bought it. The frame was coated. It has gathered road dust and Black Hills mud from the trails. It comes with the tow bar. To me the frame is solid. Reaching in holes seems clean. We towed it behind a pickup camper to the hills. It tows great. Everything works great and is ready for some fun!
I have my suspicions, but frame photos would help a lot.