At my last employer, they automatically deducted half an hour for lunch for the hourly employees if they chose to not take a lunch. There was an employee there that usually did not take lunch and essentially worked for free for half an hour. Of course, the bosses loved this and caused them to treat him favorably over the rest of us that went to unpaid lunches.

Missouri statutes doesnt have anything that addresses lunch breaks, essentially leaving it up to the employer. I dont believe my last employer had anything in their handbook about lunch breaks. It seems to me that if there is no law about lunch breaks in Missouri (and assuming it isnt covered by some federal law I am not aware of) that the employer is obligated to pay the employee for the entire time that he works and not take away half an hours pay for a lunch break that wasnt taken.

Any thoughts about this or any potential legal plan of action suggestions would be appreciated.

You are correct that Missouri has no regulation that requires meal or rest breaks be provided. Neither does federal law. If an employer does elect to provide breaks, you are also correct that the time must be paid if the employee works through his or her break time.

It appears your question is what recourse do you have if a co-worker worked through his lunch breaks, wasn't paid for the time, and now is being treated more favorably by the bosses? The answer is none. The co-worker can file a complaint with the State for his unpaid wages but you have no standing in that situation. The bosses liking him better because he always worked through his lunch break is not unlawful.