According to labels found in a couple of instruments manufactured in 1736, the Cremonese master was 92 years old at the time of their manufacture. The ‘Spencer Dyke’ was produced in that very year, and in order to appreciate its characteristics, it may prove useful to consider Horace Petherick’s take on Stradivari’s lifelong activity: ‘Stradivarius was one of those few men who, in aiming at perfection, so far as it is possible for humanity to attain to it, never swerve from the path, which may conduct them thereto: men who suffer nothing to divert or turn them aside from their object; who are not discouraged by fallacies, but who, full of faith in the value of the object they have in view, as well as in their ability for its realisation, continually recommence that which they have done well, in order to arrive at the best possible result. To Stradivarius, the making of stringed instruments was the whole world; thereon he concentrated his entire self. […] The prolonged existence of ninety-three years, […] was entirely passed away in a quiet workshop, before a bench, with compass or tool in hand.’ The Hill Brothers had previously remarked how Stradivari never left the path that he had chosen so early in life. In fact, the technical principles behind his early instruments could be recognised in his later handiwork, although some of the later instruments’ details revealed the merciless effect of his old age, like the diminishment of his eyesight and a slight tremble in his hands: ‘The veteran has in nothing forsaken his principles of form and construction; he steadfastly adheres to them as long as life leaves him the use of hand and sight: in fact, model, form, curves, edges, sound-holes, purfling, and head lack nought but the power of execution and the firmness of hand of former years.’""
More information: Antonio Stradivari Set 1, Volume 4, Page 304