I don't think legislation is the right avenue to pursue. The purpose of your excercise is to get hunters to stop displaying animals and sway the general population to the opinion that hunting is not a negative aspect of society. Getting legislation to pass on this will result in animosity and resentment.

My recommendation to you would be to attack this problem more from an education/evangalistic perspective. In New Hampshire, there is a section in the hunter education program that addresses public perception of hunters. One of the issues described is public display of game harvested. The recommendation is to close the tailgate of the truck assuming you are using one and not allow any part of the animal to be exposed.

Why not talk to your local hunters to get their buy in not to display their harvest. Then you can get support from non-hunters so they understand what you are trying to do. Try an experimental period where all hunters (or as many as you can get access to) agree not to expose their harvest. After the period is done, poll the general population and get their impression of the excercise. This will accomplish a few things:

1. No resentment from local hunters.
2. Good understanding of how senisitive an issue this is for you locally.
3. Good PR with general non-hunting population
4. Real case study you can use to take this to more of a statewide approach if needed and proven successful.

Good luck