EBP (Sherman and sometimes Goodmark) products are of good quality and the panels are very useable. That said, I have seen that the majority (not all) of the AMD parts are superior and obviously different than their competitors. From my experience, all reproduction panels will require some amount of adjustment for a desirable fit. Also, all panels should be test fitted and clamped in place to assure fit. This should be done prior to welding and primer.
If for some reason you receive a defective panel, it can be replaced or refunded (excluding shipping) as long as you have not primed, welded, ground or beat it with a hammer.
The parts available today are far superior to the older parts and tooling that were available during the late 90's and mid 00's. The parts primarily had a galvanized finish and the fit was very poor.