It could have been 10 years old even, the point is that they can use it to build better missiles. This can happen both because their missile were terrible or be

It could have been 10 years old even, the point is that they can use it to build better missiles. This can happen both because their missile were terrible or because now they can copy the solutions you used 5 (or 10) years ago. unless that particular model was a certified crappy missile that could not work in any way and that was a plot the have them lose time there is no reason to give them an old missile.