The size of the correction is visible once the dates are set side by side. The accepted record opens four-lens telescopes in 1643 to 1645 [4]. The date Moreno Madrid names, conditionally, is 1630 at the latest [5]. That is a move of 13 to 15 years [17], which is a lot in a field where almost no hardware survives, and it is a decade and a half rather than a generation.
The word carrying the load in Moreno Madrid's own sentence is "if" [5]. So it is worth laying out the chain link by link. Historical accounts have Galileo presenting one large and two smaller telescopes to Philip IV and his wife, angling for the longitude prize [13]. Their optical configurations, Moreno Madrid notes, are unspecified in the documentary record [16], so they cannot themselves confirm that Galileo ever built a four-lens instrument. Moreno Madrid suggests the telescope may have reached the Marquis of Mancera as a royal gift for his service to the court in Madrid [14], and Mancera's correspondence with that court contains no further mention of it [15]. What ties the object to Galileo, then, is the phrase in the manuscript itself: "fabricatum a Galilaeo" [2]. Thirty-six years separate the earliest proposed manufacture from the writing of the description [18].
The circumstances that produced the document cut both ways. The viceroy, suspecting Munoz of talking the king into paying for his voyage home, handed him the instrument and told him to analyse it properly [8]. A man auditioning for royal patronage has every reason to be thorough, and also every reason to make the object in his hands sound worth the trouble. The thoroughness is on the page regardless: a reverse-tapered terrestrial telescope with an erecting eyepiece and convex lenses spaced at twice their focal lengths, plus diagrams and drawings [9]. That is specific enough for historians of optics to test against what workshops were demonstrably capable of around 1630, which is the sort of check that can move an attribution without any new archive turning up.
The thing the manuscript does not tell you is whether the four-lens configuration was Galileo's own or a later fitting on something he made. It also cannot be checked against an object, since none of the eight surviving telescopes from the first half of the century is unequivocally his, and the two credited to him in Florence are not universally accepted [11]. He said he had never sold a telescope and never would [10], and he wrote no technical analysis of his own instruments [12], which is exactly why a third party's component-by-component account matters even at second hand.
There is a wrinkle Moreno Madrid flags himself. If the attribution stands, the most detailed technical description of a telescope demonstrably made by Galileo would describe a four-lens design rather than the two-element arrangement that carries his name [5]. That would make the four-lens design, not the two-element telescope bearing his name, the instrument that documents him best.
