Harpsichord Trio in B-flat major, Z.87 (Pugnani, Gaetano)

Movements/SectionsMov'ts/Sec's	3 movements Allegretto Adagio Minuetto
Genre Categories	Trios; For violin, cello, harpsichord; Scores featuring the violin; [5 more...]Scores featuring the cello; Scores featuring the harpsichord; For 3 players; For flute, cello, harpsichord; Scores featuring the flute

Sheet Music

Flute (Violin)
*#268786 - 1.22MB, 4 pp. - 0/10 2 4 6 8 10 (0) - V/V/V - 106×⇩ - JP3

PDF scanned by US-LOu
JP3 (2013/2/7)

Basso (Cello)
*#268787 - 0.88MB, 3 pp. - 0/10 2 4 6 8 10 (0) - V/V/V - 70×⇩ - JP3

PDF scanned by US-LOu
JP3 (2013/2/7)

Publisher. Info.	Manuscript parts, n.d.(ca.1790)
Copyright	Public Domain [tag/del/mrg]
Misc. Notes	Harpsichord part missing. RISM-A/II-000124608 This item forms part of the Ricasoli Collection at the University of Louisville Music Library.
Purchase	Javascript is required for this feature.

Work Title	Harpsichord Trio in B-flat major
Alternative. Title
Composer	Pugnani, Gaetano
Opus/Catalogue NumberOp./Cat. No.	ZT 87
I-Catalogue NumberI-Cat. No.	IGP 5
Key	B-flat major
Movements/SectionsMov'ts/Sec's	3 movements Allegretto Adagio Minuetto
Composer Time PeriodComp. Period	Classical
Piece Style	Classical
Instrumentation	harpsichord, violin or flute, cello

Help me out here. 3rd instrument "unspecified" according to RISM; on what basis do we say it's a harpsichord?