Hello Jeff and welcome to the Forum. I'm currently finishing up restoring
my 75 Argosy 28 and can say that it takes some patience and alot of
questions to my fellow streamers. First thing I did was measure the rear
end hieght from the ground and the seems along the rear to check for
seperation. I also would advise checking the axles a trailer of vintage
quality may have some bad/ worn axles, which would give the back end a
droop. I replaced the front section of my floor by first taking the banana
wrap off and then removing everything that would be in the way on the
inside. Remember just reverse the reinstall. Basic carpentry 101 took
over after that. If yours are just soft spots you may be able to delay a
major undertaking till after you did some camping

. The exterior of mine
looked bad, but turned out to be in great shape, the aluminum portions
anyway the endcaps had to be painted. I've posted pictures showing the
disassembly of the front and rear floors and also the painting of the
endcaps. depending on how long you plan on keeping the trailer and the
use it will get may determine how much money your willing to spend on a
great trailer. I recommend fix it a little at a time and go camping with the
rest of the time.
Keith