A ship needs a frame, to hang doped paper, balsa, or whatever "skin" onto & keep the proper shape. Fiberglass is commonly used, with "windows" cut out to give the effect of a ribbed frame. Shots can easily penetrate the sking between ribs, so high power isn't needed. I think that's what the OP is proposing to do with his plastic model, not fight it as-is.

JM