The white piece you call the 'pick-guard' is what we'd call the scratch-plate. It is held on by small dome-head screws in ALL CASES but they can be slot-heads or cross-heads -about 3-4mm in diameter.  You really need to boolean-out recesses for these screws to make it look right.

The BRIDGE is the lump at the end of the strings on the body - lol
It can have many parts, including 'micro-tuners' (as we used to call em) or saddles as they are on your graphic. Beneath the bridge would be the springs for the tremelo arm system or Whammy -bar, but it doesn't look like you are going to show the back of the instrument so that doesn't matter here. 

I don't see any position dots on the neck of your model. Checkout guitar websites to see different designs. Fender usually have just plain round ones but others like Gibson have parallelogram shapes. These are invariabley made of 'mother-of-pearl', also some guitars have corresponding dots on the top edge of the neck so that they could be seen more easily by the user.

You will also need to show a recess for  the TRUSS ROD.
Love to see a hi-rez render!

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