The two missing components are identical to the one directly below it (assume the three to be line, pointing to 11 o'clock). there are no schematics availbel so I can;t sy for certain what they are but they appear to be either Zener diodes or bidirectional TVS diodes to protect the input/output line.
Here are some examples from different schematics. These are not the missing parts on your board but can serve as a reference.
[image|1389899]
[image|1389898]