I will post more tonight at home as there are a few here on the forum that have had a corner strip off and back on. What I do not know is on the sides of the camper is the aluminum siding bent over the front and then the corner molding put on over this. Forum members Frank, VCRT, Lode and EMD_Driver have been into those corners and know what is under them. I’ll hunt for some of there posts that have pics.
Now to your 2005 1950, OK that is a new coach in this perspective. I was thinking one of the older tan ones you might have in the 60’s or 70’s. Your 2005 is built like mine and many others here on the forum. And those front corner seams after a number of years are concerning. I myself just Dicor’ed them, I have no water and I want to keep it that way. But my sealing tape is sound right now but I can tell after 7 years I can see signs it looks like it might be lifting up off the aluminum. So took precautions as this camper has lived outside all it’s life. My prior T2499 lived inside most of it’s life and it has not seen these weathering effects.
Since you have what appears as a soft spot inside my bigger concern now is how much wet is in that wall?? I do not want to scare you as if we had some pictures of what you are seeing it will help show us what you are looking at and that will help guide a better response to offer some fix it suggestions.
Now to that corner itself, it looks like this. This corner is on my slide. Here they did not bend the siding over to the side of the slide. The ends of the camper may be made different but this molding piece is attached very similar. Here is my slide flange I just repaired.
If you for sure have water entering in the corner molding and not the top front seam of the camper, then my 2 cents is to remove the corner, check for wood damage if you can see it with the corner off, then put on new fresh Butyl sealing tape and put the corner back on. “IF” you have a water flow channel under the existing putty tape putting a little dab of Dicor or any other sealant on the outside may only be a temporary fix. The sealing tape is 1” wide to stop a path of water. The caulk on the outside is only maybe 1/8” thick at it’s thickest. Yes the caulk will seal it but you are going to have to be a super hawk eye to make sure there is not crack in time that comes from it.
If the wood/insulation is wet then you know and can deal with it now. If you seal it up now, it may be a few years before it will rear it’s ugly head. You may not have to take the siding off the camper, you may have caught this early enough and the repair is not to bad.
To check if the insulation is soggy, take off the yellow clearance marker light. There is about a 1” hole in the siding that you look in and put your finger in there to check for wetness. Granted this is only 1 spot and it may be dry, but if it is wet, then you know for sure you have a problem to deal with.
Up top on the front of the camper is a seam from the roof to the front siding. Are there any cracks in that caulking? The water may be coming in from above and not the corner molding.
Hope this helps and any pics you have are real helpful in cases like this. I may be over reacting or not.