Big Decission Purchase Question

Hi Everyone: Maybe some could see this question coming. I am looking at purchasing a 2005 1181 Lance which is clean inside and has a water tight roof but showing some concerns on outside walls. There is a tapered bulge in the lower middle exterior wall of the slide-out about 6" in width and 1 foot high. I estimate it is a good 1/8" in thickness. The present owner for the past 4 years has indicated it has not changed in that time. When applying heavy exterior pressure by hand the bulge feels quite firm - no movement. There is no evidence of deformity on the inside wall of the slide under the table or under the slide. It looks like moisture at one time has been allowed to enter the interior wall along the bottom seam and swelled the plywood and hence been re-sealed. Could this bulge (after 4 years) be considered to be in a stable condition and not get worse? Please see picture.


There are other lower seams that need to be re-caulked as soon as possible but they do not appear to show any signs of swelling yet.
See picture.


Any words of wisdom/caution/experience would be appreciated. I understand the final decision is mine. cheers christl
By tomorrow afternoon any comments won't make any difference.