Not a bad start but…
You will probably want to install Thom Thom’s Solid Inspector2 from the Extension Warehouse and use it on your components. Here’s what I get when running it on this one.
There’s a lot of bad geometry that needs to be cleaned up. Solid Inspector can do some of it but not all. You’ll also need to correct face orientation so all white front faces are out.
Also, do you really want that step at the transition from the arc to the flat?
One thing you would find useful is to increase your precision and turn off length snapping in Window>Model Info.
I took a few minutes and redrew it. Since your dimensions were weird due to the lack of precision when you were modeling, my dimensions may not be correct.
FWIW, I uploaded the model to SHapeways out of curiosity as a test of printability. Looks like it should print. The curved rim at the top needed to be thickened a bit, though.