This is a kind of common issue with fiberglass over aluminum framed trailers.
It is caused by either water intrusion or heat — it basically is the fiberglass skin on the front cap becoming de-laminated from the material under the fiberglass.
An aluminum replacement cap will be stronger, and if done properly will eliminate any future leak issues — and look very good. The proper “S” overlap joining is critical (just like installing roof shingles on your home).
While this may seem like a daunting repair —it is not really that tough or expensive to accomplish. And it will look spectacular when you are done.
Front window, mouldings, and market lights must come off first.
If it is done like this fellow did it — it will both improve your 160, as well as increase its value, appearance, and it is well worth doing.
This guy said he did it for $500-$600, DIY (don’t know when). But even if you shop around for an INDEPENDENT Quality RV repair shop — it shouldn’t run more than $2000 to $2500.
This front cap replacement is a common job on many trailers.