The key factor is its content of formaldehyde.

It didn't hold up well and it was highly toxic due to all the formaldehyde and other chemicals used in the curing process.

Just for a caution Damp Rid is actually formaldehyde and can also affect a person's senses if they come into the home.

There isn't a lot of evidence that weed has been laced with fentanyl but there is a long history of it with other drugs.IE - Cocaine, PCP, ketamine, formaldehyde, heroin, LSD, meth, and others.

Additionally lot's of particle board was laced with formaldehyde which is a caustic chemical.Formica counter tops are known to have been laced with formaldehyde as well.Acoustical and popcorn ceilings in that circa were known to have asbestos in it which is a highly carcinogenic chemical and can be very detrimental to ones health.Above ceiling and wall insulation was also know to have asbestos in it.A lot of plumbing in those days was made from "Quest" Poly Butylene which proved to be catastrophic and ended up costing Shell Oil huge losses in a class action lawsuit in order to cover court ordered replacement on hundreds of thousands of mobile homes.Finally, once you start going down that road it will be like feeding a cancer that just keeps manifesting itself. 

It wasn't uncommon to utilize lots of formaldehyde and asbestos so don't just start pulling things apart without first having everything inspected.

If it was some cheap laminate from another country that might be the cause of the smell....Frank Frank has a point, Lumber Liquidators was recently sued for its laminate having too much formaldehyde in it.  

The content of formaldehyde BF is mainly made up of glued bamboo planks, while the support material of LF consists of glued wooden fiber.

Moreover, Brokers and salespersons similarly have no special training, knowledge or experience with regard to evaluation of possible environmental conditions which might affect the Property pertaining to the dwelling, such as the existence of radon gas, formaldehyde gas, airborne asbestos libers, toxic chemicals, underground storage tanks, lead, mold or other pollutants in the soil, air, or water."

MH's manufactured before 1979 are inundated with formaldehyde, asbestos and myriad caustic and carcinogenic the only way to deal with this issue if you're really going to be investing in multiple MH's is this:If you're going to do a remodel you may as well do it all the way.