About this 3D model

This is to replace the tray retaining clips on the Mothercare Convertible Highchair. Product info here: http://goo.gl/Yks20 The pegs broke off our one which meant the tray could easily be knocked off by a boisterous child. I could fix it with epoxy and doweling but this gives me an opportunity to learn some 3D modelling, which in this case was using Sketchup. This is my first model, so if anyone has some tips regarding making it printable, modelling techniques etc please get in touch. I have uploaded two versions. One which is unprintable but is an accurate model of the existing clip, the second has supports included which can be trimmed off but these will probably need revision as I am a n00b. I have uploaded the Sketchup files and also the converted STL files.