Yeah, my parents paid over $70,000 for this place in 2001. Wasn't worth the price in my opinion.It is most likely a HUD code home.
The applicable Federal Standard requires a data plate "affixed in a permanent manner near the main electrical panel or other readily accessible and visible location. Each data plate shall be made of material what will receive typed information as well as preprinted information, and which can be cleaned of ordinary smudges or household dirt without removing information contained on the data plate; or the data plate shall be covered in a permanent manner with materials that will make it possible to clean the data plate of ordinary dirt and smudges without obscuring theinformation."
I'd look for the data plate near your breaker box or where the electrical utilities enter the home. That said, the company may not be around any longer. Since I've been in the industry there have been a number of closures, mergers, acquisitions, etc.. It's not the same industry it was 20 years ago.
I've been serving the manufactured housing industry since 1994. Chances are that the windows, doors, bath fans, range hood, water heater vent, attic vents, and select other parts were manufactured by companies I worked for. Your observations regarding the quality of construction are an unfortunate reality of certain classes of manufactured housing from that era. The mandate from HUD when the standards were developed was for "affordable housing". The lowest cost solutions to nearly every requirement were sought out and in fact encouraged. I'm pleased to say that every year I've been in the industry there have been improvements.