What stood out to me in GL's original costume were the colors. I applied the color scheme to a Victorian era gentleman's suit. I added to the Victorian era lantern. I used the green goggles to look like the mask and protect his eyes from the bright light of the lantern.
The only problem I have with this figure is that he doesn't have the Green Latern Insignia anywhere on his suit. Green Laterns may wear a variety of outfits, but they're all just variations of the same uniform. Without the insignia, its just a guy in a green suit, using a power ring.