Epson very quickly responded to a separate email I sent to them. The change had to be made on the DVD player. When that is done, the projector follows and displays 4x3 films correctly.
On the Epson 8350 and maybe other projectors as well it says the aspect ratio is set automatically and cannot be changed for 720p 1080i and 1080p signals. But for 4x3 films this results in squished images that are out of proportion. Anyone know why this cannot be changed and if there's a workaround?