Well I was able to track down the omission from Boalch. This instrument
is officially listed as a fake Ruckers.
Taskins name and date 1774 are there but the HR 1612 has been the name
given for 50 years. Grant Obrien mentions on page 211 of several totally
flemish harpsichords rebuilt in France and sold off as genuine Ruckers.
He spends a paragraph on p 278 where he mentions the 4 registers and
peau de buffle.
It boggles my mind that no one thought to correct the third edition of
Boalch/ It only appears with the others Ruckers in the Hans section.
Thanks for calling our attention. I tend to reach for the books
before the articles. Jack Peters