The pipe is the vent for the black water tank. Pull that chrome bezel off the top and make sure that seal is ok.
I'm getting ready to replace the floor from a leak and I suspect that is where the leak was. My Father-in-law was the PO of ours. He recently caulked up that vent to fix a leak I was told by my Brother-in-law. Was a lot of freash caulk under the bezel. From what I have seen the correct seal is a peice of rubber or foam rubber and some Valchem around the pipe. Inland RV may be able to get it if not it would not be hard to make if you can find the material.
Well I have some pictures but they are in the Airstreamphoto's. That's down right now. Some problem with the software and a firewall. Should be up soon.
Looking at your picture...WOW it's in such great shape! I wish ours was half as good of shape as that. We are missing the RV fridge. I wonder if ours came with a Marvle like your or a newer unit. My wife always remebers a square face fridge like they show for the 59 at www.vintageairstream.com
Our cabinets are a little different. We have a open shelf over the fridge instead of the full cabinet to the ceiling. Our table folds into the wall so we don't have the lower street side window at the table.
Ours was the first year of the forced air heater that is located in the side of the cabinet with the stove instead of the radiant unit you have next to the door. That slim door on yours is not on ours. The fridge is all the way to the door and that space is included in our wardrobe that has double doors.
59 was a year of a lot of first. Our windows are a little different and don't have the curved perimiter and the mutton bars. The wheel opening changed shape also. Our battery was mounted below the front window.
Our water heater is located under the bed becide the storage door. I don't see a heater cover on yours there. Where is it mounted. I don't see the access pannel on either side. unless it's under the fridge.
It looks like our galley overheads are posisitoned differently as well. to the right of the sink our overheads end flush with the end of the counter. Then we have one over the bed.
Yes we have both the shower and bedroom folding partions. My understanding is that Lowes or HD have some that are very simular that a few people have substituted. I need to replace one because my Father-in-law managed to shoot it and the reefer door in one shot. LOL The reefer door was what kept it from goint through the front of the trailer. He replaced it with a 110v unit.
I have been staring at your pictures for 30 minutes. I just cant get over how good of condtion it's in. Really gives me something to work towards. Is that the original zolotone or has the walls been repainted?
What side of town are you on? We will have to get together sometime.