Stevens single shot 20 ga Model 9478

I have a Stevens model 9478 20 ga single shot that was given to me by my dad many years ago as my first gun. Killed my first two turkeys and many squirrels with it. I have kept it clean and it still shoots great. It's value is probably only $100 bucks or so, but the sentimental value is off the chart for me. Now, I want to pass it down to my son. I need to find a trigger guard for it as the original one has a crack in it. It's one of those one piece plastic deals, and if I have to get another plastic one then so be it, but I wanted to check first and see if someone on here knows of anybody that makes or sells aluminum(or something stronger than plastic) trigger guards for this model. Thanks in advance for any input.