[DCRM-L] chapbooks: SH or FG?

[silvanan at mptek.net]

Hello all,
I am doing special collections item-level cataloging for a collection of
modern Brazilian chapbooks and I wasn't sure if I should include
"chapbooks" as a 650 SH or a 655 FG, or both. And, of course, other
records I checked are allover the place on this. I would be inclined to
read an unqualified 650 as a book "about" chapbooks, but so many records
include them for actual chapbooks. I'll probably end up second guessing
any independent decision I make at his point, so thoughts or advice on
practice would be appreciated.

So:
650 Chapbooks, Brazilian.
or 
650 Chapbooks, Brazilian|vSpecimens.
or
655 Chapbooks|zBrazil.|2###

Or some combination?

Thanks,
Silvana