A/C Replacement and Trailer outside steps - repair questions

[jjustice]

Well, the saga goes on about the AC replacement of the Armstrong 10 to a Dometic Duo Therm Air Conditioner on my '78 Argosy 27'. This is my question: The new AC is securely mounted to the top of the Argosy but the interior shroud that covers the hole and directs the air is not rounded like the original shroud on the Armstrong. The new one is made for a flat ceiling so when installing it to the top of the ceiling in the AS there is a gap of about 1” AND the controls on the new AC do not extend far enough to be hooked up. I need some guiding suggestions here as to how to solve the problem of attaching the new inside shroud to the new AC w/o having a big gap on the ceiling due to the shroud not being rounded.
Second issue that has just showed up is this. The outside steps (an original two step system on the Argosy that folds up and locks into place under the belly of the AS) the right side has come out of its slotted channel. Has anyone had this issue? And if so how did you fix it? I tried to work it into position but it will not stay in place (right side). The left side is still in the channel and has not come out but I am afraid that if I attempt to force the right side I will risk the chance of having the left side come out also then the whole step assembly would just be dangling there. WHAT to do? Thanks jjustice