As in the 1950s, the standard mobile home of the 1970s would have come fully-furnished. However, the quality of articles used had fallen drastically. Interiors were often done in gaudy "Mediterranean" decor and furnished with low cost accessories, such as this "Spanish" -style sofa. The only thing missing from such an interior decorating scheme might be a tacky "Velvet Elvis" painting...
The lower-to-medium price mobile home of the early 1970s was often floored with low quality "shag" carpeting. Garish shades of red & black, orange or bright green were common.
Quality issues and dubious features, such as cheap (and potentially dangerous) aluminum electrical wiring, caused the US Congress to pass stricter standards for construction in 1974.
The National Mobile Home Construction & Safety Standards Act became law in June 1976. To get away from all of the negativity associated with house trailers or mobile homes in general, the product name was changed to "Manufactured Home", which was federally mandated in 1980.