Original sentence: "  Yet the oval spinet did not catch on in Cristofori's day, and there is no evidence that any further such instruments were ever constructed until Chinnery and Schwarz built their replica.Musical instrument scholar Stewart Pollens has called the oval spinet "a tour de force of mechanical design, fully the product of Cristofori's inventive character.Pollens, Stewart (1991) "Three Keyboard Instruments Signed by Cristofori's Assistant, Giovanni Ferrini," The Galpin Society Journal 44:  77-93.Why this is so must be a matter for conjecture
Edited sentence: The oval spinet evidently did not catch on in Cristofori's day, and there is no evidence that any further oval spinets were ever constructed until Chinnery and Schwarz built their replica.Why this is so, despite the cleverness of the design, must be a matter for conjecture