Got some chainguard info,
from Honda partsbook June 21, 1971.
#40510-300-040B up to #1021,879
#40510-300-050B #1021,880 - #1022,649
So I assume they are both plastic, as I have had the short one and now have a 26 inch plastic one.
Instrument faces, I had a set that were not real faded but very yellowed, the came out real nice after polishing with Meguiar's. I think is what I used , comes in 3 grades..I used medium.