Fettling chainguard

Original MK 111 chain guard looked worn out cosmetically , showing weak chrome on the show side exposing what looks like the copper under plating. New one much chromier , fitting it and it's fiberglass extension took some work.
First the extension. The new guard was not pressed square at the fiberglass extension like the original , more rounded. Plenty of filing down to get it to fit into the guard upper slot. Then magic marker to the attach holes locations and 1/2 " drilling to both fiberglass sides that came with no holes to mount it. After the 2 caps and spring flew across the room several times trying to secure it I changed tactics , put grease to both caps to hold into place , then used needle nose pliers to totally compress new spring and wiggle into extension sweet spot.
Next pushed into the guard until the 2 caps snapped into the home holes.
2nd issue. The shock mount slot was too narrow to fit over the special shock bolt. Dremel tool time to enlarge the guard slot gradually , refitting and checking until voila. You need a very narrow wrench to get in there to hold it tight whilst tightening up from the lower shock mount side.
That's it , hope your fettling goes easier.

Mine has the exact appearance you describe. My thought was to get it re-plated... someday (low priority for me). Great reminder that some replacement parts are all too often sadly lacking in (functional) detail.