The instrument I offer is based on the original flute in the Nuremberg Museum (ref. 297 MIR, circa 1775) and also on other instruments that I have been able to measure.
The original instrument has seven extra middle joints. It is made of stained boxwood with ivory rings, a silver key and a tuning slide on the foot joint. The mouth hole is relatively small.

I offer a copy of this flute, in stained boxwood or grenadilla, with imitation ivory rings, silver key, and a tuning slide on the foot joint, pitch a=415 Hz.

I also offer an extra middle joint for a=430 Hz.

You can have also a head with elliptical mouth hole for classical style. And it's possible to have two heads for the same flute, one with round mouth hole for the baroque style, and other with elliptical mouth hole to play with the extra middle joint for a=430 Hz for classical style for exemple.

The Grenser flutes are characterised by a narrower bore than the flutes of his contemporaries, making it easy to the high register, exactly the opposite to J.J. Quantz’s approach during the same period at the Dresden court.
The sound is sharp and cutting, with a third register (to the A) easy and bright.
Repertoire : all the music in the mid to late 18th century, CPE Bach, Haydn, Mozart, ...
Carl August GRENSER (1720-1807) : after being trained in Leipzig, CA Grenser founded his workshop for wind instruments in Dresden. This workshop has become one of the most famous in Europe and received Royal Approval in 1753. Around 1780, he was one of the first in Germany to make instruments with additional keys. His nephew, Johann Heinrich Grenser (1764 - 1813) succeeded him in 1796.

Transverse flute in D, a=415 / 430 Hz
wood	net prices
boxwood a=415 Hz	1320 €
grenadilla a=415 Hz	1395 €
additional head	450 €
extra middle joint for a=430 Hz	270 €