Antique writing desk

Does anyone have any ideas about this desk? It has a key that appears to be hand forged, the locking mechanism works. I believe it's a slant front style writing desk but I'd like to know what era this was from, what type of person would have used it, really anything! It's quite heavy and approximately 2.5x2 feet. I'm unsure of wood type but it has a redish hue and teeny tiny holes, like dimples, on the side and back boards. The only markings I can find are a "P" and possibly a "C" burned into the underside of the lid. There is also a series of tick or tally marks scratched into the lid.