Need a cover for ashdown mag 300

[jarrydee]

I know this is out of the ordinary, but I need to save money so....I am going to use the head out of my ashdown mag 300 combo, it unscrews and pushes right out, BUT...I need to figure out how to build or have one built, a cover for the top and sides...Is this possible, or should I just use it wide open? Thanks everyone, you all have helped me a lot since I joined here, I am new to all of this!