I own two old Hi-Lo's now. Both are 24'. One is a 1984 and the other is a "Classic" 1990. I also owned a 24' fun chaser and it was an 04 or 05 don't remember exactly. All these trailers were good but in my view the older Hi-Lo's were much better built in every respect but particularly the materials used inside the camper. My 1990 Classic is a super well made luxury camper on par with modern day Forest Rivers but even better.
I keep both my Hi-Lo's washed and waxed but MOST important I store my Hi-Lo's in either a garage or in car ports. If you buy an old Hi-LO that has always been exposed to the elements you will have many more issues with it as a general rule. It only cost me 1,200 bucks to buy a steel carport at Menards and they go up easily if your a little handy. Keeping your trailer out of the direct sun, rain and snow makes a big difference. I say if you can find a nice old one like I did, (twice) you will love the quality of your older Hi-Lo. I also knew a factory certified Hi-Lo tech and he confirmed the old ones are better if you can find a nice one.