Volfandt, the first thing I would suggest is to get your hinge pins right. The reason your striker plate is gouged is due the badly worn latch. This happens to all of them over time as the hinge pins wear out, and the door sags causing excessive contact with the striker plate. After you tighten up your hinge pins, then you will need to address the irregularly worn latch. You may need to weld some metal back on it and grind it to the original shape. Check the welds on the latch, as they often pop loose.
