Matrix:
You have the right idea, but I think you need to find some finer wire for making those periscope guards. Try to find some fine craft wire -- they sell spools of it in the jewelry sections of craft stores. Copper or aluminum wire is good for this sort of thing -- easy to cut and bend, but stiff enough to hold its shape.
You can also use it to replace the handle on the hatch -- shave off the molded on handle, drill a couple holes where the ends are and glue in your replacement handle.
I'm not really sure why you replaced the lift rings to begin with (lose one or two of the kit parts?), but that paperclip wire is about the right size -- but really too big for much else. Paperclip wire must scale out to about 1-2 scale inches thick, depending on the wire. Look for wire about 1/4-1/2 inches scale inches thick -- thinner than a 1/35th scale figure's finger.
You are on the right track -- keep going!