sentences:  By 1975, approximately 1000 of these instruments had been produced.Some of Hubbard "kit harpsichords" have been (and still are now in the 21st century) used as first-rate instruments in public recitals worldwide.An amateur violinist, he also restored a number of early violins to their original state and made early (pre-Tourte) bows for instruments of the viol and violin families.