Sailor Suits (#20) are made of heavy cotton fabric, almost jean heavy. They all are. Sometimes the fabric is slightly different, Taiwan vs. China, but it’s still a heavy cotton material. Right?

Apparently not. Recently, I acquired a Sailor Suit made of thin cotton material, similar to the material used in the 1983 dresses. It’s hard to see the difference in the picture, but it’s there.
The accent cord appears to be different as well.

However, everything else is the same. Same patch, same structure, same sizing . . . even the same tag! That’s right, it’s tagged KT factory.
Why?
My only theory is that they ran out of fabric but wanted to continue production. They grabbed another red material that they had handy from making other outfits and continued the run. Another factory fluke.
What do you think?
What else could have caused this to happen?
Have you ever seen something similar?