Modular pins display board

I'm a pin collector, I've been collecting them from all over the world, my friends also buy them for me from their travels. I made an Europe map pin display board but because I have many pins sometimes from one country/region (eg Italy) I decided I need a second board system for my additional pins and for pins from outside EU. This is a simple project, I made the board 20x20 + hook because this is the most that can fit on my printer table. The holes are sized for clasic pins. The board is quite thin but pins usually have short nibs so I add a bit of poster tack under a pin for secure mounting. Table has a hook for mounting on a wall and also a small peg on the bottom for mounting additional boards to the first one