I'm not a huge mod guy but Gimli is so prominent in the movies that he deserves a place on my pin (Legolas too but haven't found a place to mount him yet). Gimli doesn't block anything from view except Balrogs side when he's at the closed position. And of course... he's easily reversible.
Materials/tools: Lexan, screwdriver, pen to mark holes, ramp flap screw, bench grinder, scissors.

TIP: Round out the backside of the plastic so that balls travelling through the wireform don't strike it. This is a rough shape that doesn't need to be exact but gives an idea of what worked for me. MOST IMPORTANT step is positioning the front mounting hole since Balrog's armpit/hand will need to clear Gimli.

TIP: Remove the washer on top of the hex spacer. Drill 2 holes through plastic... one to mount to hex spacer, one to mount Gimli. Use a ramp flap screw to secure Gimli's front foot. No drilling required into his foot, there already is a cavity.

Shape of front edges not that important. Make piece long enough so Gimli jets out into the front of the wireform ramp so that Balrog doesnt' hit Gimli or his axe.