Kevin, nope, not a typo.
I emailed the University of Edinburgh and received a reply from a splendid fellow by the name of Dr Arnold Myers, who is the Director,
Edinburgh University Collection of Historic Musical Instruments.
They have a Card’s Improved in their collection, and for posterity here’s what the good Dr had to say about what’s described in the museum catalogue as a D flute (conical bore) in C:
AN: (44)
EN: Flute.
Nominal pitch: C.
TS: Card’s system.
Maker: Card & Co.
PL: London.
DM: 1845-76.
FM: William Card was active as a player in London 1825 - 61, and had his instruments built by Whitaker who was formerly an employee of Rudall and Rose (Toff 1979, p.104). He was succeeded in business by his son Edward in 1861 (Waterhouse 1993, p.57).
Overall size: 652.
Bore: conical.
Technical description: Rosewood; 4 sections (body in one piece); silver keys; 5 chased silver ferrules plus cap; engraved silver embouchure-plate and bushes for L1, L2, L3 and R3 finger-holes; metal-lined head; tuning-slide; long screw-stopper; rectangular embouchure-hole; metal-tipped tenons; adjacent low C/C-sharp touches, with roller ends on shanks; rods down both sides of instrument; many duplicate touchpieces; D trill requires right hand to move from normal position.
L0: B-flat; C.
L1: T.
L2: T.
L3: T.
L4: G-sharp.
R1: F ring; dup G-sharp; D trill.
R2: E ring; dup C.
R3: T; dup B-flat.
R4: E-flat; low C-sharp; low C.
Keyhead type: Cylinder cup.
Keymount type: Rod/pillar; needle springs except for B-flat, duplicate C, D trill, low C/C-sharp (leaf).
IN: Engraved on silver plate on head “CARD’S / Improved” (in script) / “PATENT”.
CS: With case, containing maker’s card inscribed “Mr Card / Professor of the Flute / & Flute Manufacturer / 29, St. James Street” (all in script), also label printed with previous owner’s name and card inscribed with fingering charts for C-sharp-7 and D-7.
Usable pitch: A4 = c 458 Hz.
Performance characteristics: [Original range: C4 - D7]. Present range: E-flat4 - A6. With screw and head set at mean position, intonation uneven and bottom notes flat.
Specific literature references: G.S. (1968) No. 55.
Illustration references: Vol. 1 p.69.
Previous ownership: W. Hilder.
CA: (Rendall Collection).