latch, aka Combination Locking Drawbolt like below. These came from Franzen products, who are no longer in business, they do show up on a website in Italy/ England but it looks like it's a wholesale outfit. I hit a couple potholes and the plastic that the lid attaches to broke, sending the broken piece with the latch to parts unknown. On the off chance that someone is using a similar latch, the other pics show the piece needed with a dimension of 2" wide.
