If the battery is white, it's a Varta and PROBABLY original.

They are supposed to punch out the year and month of purchase, that's how you know when the warranty starts, so yes, there should be indication of install date.

The fuel pressure regulator and fuel filter are all in one unit. They sell in the aftermarket world for about $30. I've never tried changing one, I think it's four hoses and four clamps, not very involved, but there will probably be pressurein the lines when you loosen the clamps, keep that in mind!