Ikea Billy Bookcase Peg Hooks

We have a some Billy bookcases set up as lockers and I was looking for a way to hang keys in them without damaging the bookcase. A didn't see anything like I was looking for so came up with this quick model. 

There are 3 different versions, a 10mm, 15mm and 20mm hook length. They are a snug friction fit into two adjacent vertical holes to prevent twisting. The pegs have a center to center just over 32mm and might fit other furniture. When using the default 0.2mm Speed Mk4 profile they print in 3 minutes and use under 1 gram of filament.