Re: Fresh water tank connections
Those systems look pretty similar to my '97, so I'll take a stab at it.
The city water fill just has the "two turning parts" because the end of a garden hose is a fixed male, and you need to be able to rotate the female around it to tighten it. The city water connection is the female. So the outer, "flower shaped" part is just a gripper so that you can turn it, and is the female that you will tighten onto the male garden hose end. The smaller black plastic plug inside the flower part, is simply a cap that takes the place of the male garden hose end when you don't have a hose attached, to "close" the fill.
If there is anything wrong with it, they are inexpensive and readily available. I had to replace mine because it froze. I had drained the water system but because of the way the van body "tucks in" where mine mounted, mine sat in a slightly "leaning back" position, and some water stayed there and froze. Of course it was also ten year old cheap plastic, so not like it was a bad thing to replace it. The back and water connections were easily accessible on mine just by reaching up behind the body panel while lying under the van.
The second photo looks like it is plumbed similar to mine, but just the end fitting is different. Anyway, I believe that "schnozzle" end is not part of how you would usually use the van, but is instead meant to be an alternative that allows you to pour water into the tank from inside (say, using a funnel). I used this feature once when I was on a trip and wanted the convenience of using the tank/sink/faucet in the van, but didn't have access to a hose to fill the tank with. I bought some one-gallon jugs of water at the grocery store and used a funnel/hose to pour them into the tank via that alternative fill (instructions explaining this were in my SMB manual that came with the van).
I don't know if you know this part already, but that grey valve handle gets turned one way (open, IIRC) to allow the hose that you have attached at the city water fill (shown in your first photo) to fill the tank, then when you finish you close it and that allows the system to pressurize again and be used normally. The reason this is there is that SMB uses the city water fill to do two jobs: Act as a pressure connection (where you keep the hose hooked up all the time), AND act as a "gravity" water fill. Many (most?) RV's have two different fills to do those two jobs; by using the grey valve SMB was able to double up the function of the city water inlet.