I am reading this thread in preparation for a similar job. Who makes, or should I say, sells these poorly made panels? and who makes/sells the best stuff?
I dont recall where I got the first one that didn't fit well but the second one that is in the picture that is to short was purchased at Jim Carters. That being said I have bought several items from Jim Carters and they have worked well with no complaints. Like Bartamos said they probably all come from one or two foreign sources so it could be a crap shoot. Knowing this now I think I would measure the length of the bottom of the panel to the top of the arch and ask any supplier if they can check the length before buying it.