Here is an E-stop key cap

I printed mine out of PETG though PLA is probably okay. 

No Supports for any of the components needed

I printed my parts at 0.2 layers with a 0.4 nozzle. If you want finer detail you can try a smaller nozzle diameter.

You will probably need to glue the mushroom part of the button onto the base.

I have provided two base models, one with a small amount of support that would need to be cut off after its printed and the other without support. I printed the no support version without issue but if you have issues with the middle piece detaching from the build plate I would try the base with support.

Happy printing and thank you for the support!