The above quintet is Pepusch´s concerto op.8 No.6. The full title of the first edition is:VI Concerts / a 2 Flutes à Bec, 2 Flutes Traversieres/Hautbois ou Violons&Basse Continue/Composée par /
MONSIEUR PEPUSCH/ VIII me Ouvrage/A Amsterdam chez Jeanne Roger/ No 434
I guess, that the quintet is incomplete, because for example No.1 and No.2 of op.8 have
4 movements, which is the standard for works of this type.
Another remark concercing the flute sonatas of Frederick II, which recently have been uploaded. The sonatas are for flute and bc,
like the other ones at IMSLP, compare http://opac.rism.info
(Enter SpiF 154 and SpiF 190 in the search window)