When I looked for these in the 1990's. I usually found them at antique stores or shows. I once also went to a quilt show.
A person there had some individual pieces that she said she would sell to me but later, when I called her, she had decided to sew them into a project she was making
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At one antique show, I found a dealer who owned a LARGE quilt that had over 130 B 18's blankets sewn around the edge with other, different types of felts sewn towards the center piece (which was a large American flag). I bought that for $600 dollars and was going to keep it for display. However, once I got it home, it was too large for the wall I was going to hang it on. So, I decided to sell it (and made a really good profit off it).
At another, smaller show, I found this pillow cover. Nice condition, smaller and easier to display and store, plus it has Joe Jackson....
David