What the devil is Best Buy 2777?

Even though I started collecting both new and old Barbies and family about 1984, one item I saw for sale still at the store then was 1979 Best Buy 2777.  This was a skimpy revealing beige and red striped thin cotton bodysuit that was called Rompers in Europe.  It had puffy sleeves but no back, and the panties section was skin-tight and gave Barbie a wedgie.  It was the cheapest looking Best Buy ever made,  and even fashion doll clothes that I find today at Dollar Tree are better made than Rompers.

That's why you could find it for sale long after the other Best Buys had sold out.  No one knew what this bodysuit was, and it wasn't very attractive.  I looked through other clothes from 1979, wondering if there was a skirt or pair of slacks that was meant to be worn with it, but could find nothing that remotely matched.  I also wondered if it was supposed to be a swimsuit cover-up, but none of the swimsuits sold that year, on the dolls or separately, matched either.

I've written before about odd outfits that I eventually figured out what they were supposed to be, but this one still has me puzzled.  Any ideas?

My 1979 Sun Lovin' Malibu Barbie
is modeling 2777 Rompers,
and finds it uncomfortable to wear.

The outfit was definitely made
for the Sun Lovin' dolls
 as its bare back shows off Barbie's tan lines.