That's the service kit from the early 90s, isn't it? I never asked why but my mechanic removed those old drains and replaced mine a couple of years ago during the annual. The new ones are beefier and work better so I never thought much about it.
I’ll try to get a picture when I can. Yes, my plane has patches, but they blend in nicely. I assumed the patch is from the late 80s-early 90s service kits. My old drains looked like yours. The new ones are Cessna S2106-2 drains, or so they appear. They flow better and seal better than what they replaced, that’s for sure. My plane is a ‘75. After reading about the old AD I found that was the first year the factory installed wing sumps as standard equipment. Maybe my “patches” were factory installed? Mine don’t draw any attention.