I bought an Amtrak diner. It has the same lines pictured above. When I run it it's barely noticeable. I've since done a whole lot of work on the car, removed the skirting, painted and populated the interior, re-painted the underside black, and weathered it. I can't find those lines anymore. I wish I took pics of the lines on the car body when I could see them, but the weathering has covered it up. Even so it was not too noticeable when running the car in a train. These diners are sooo much fun!! With the train sounds. And Timmy!!!! I like Timmy. This is my 2nd Lionel dining car.
I hope you can find one without the lines on the shell. If not; it's not too much of an eyesore and Timmy makes up for it 😜 I have enjoyed watching you detail all these pennsy and PC cars!