Abraham Robinson worked in applied mathematics for several decades. MathSciNet lists 12 articles by Robinson in wing theory. His production included the book

Robinson, A.; Laurmann, J. A. Wing theory. Cambridge, at the University Press, 1956.

The book is full of references to infinitesimals. Thus on page 36 one finds a reference to "infinitesimal horseshoe vortices of constant strength". Five years later Robinson published his first publication on infinitesimals in

Robinson, Abraham. Non-standard analysis. Nederl. Akad. Wetensch. Proc. Ser. A 64 = Indag. Math. 23 1961 432–440.

Are there any sources or references in the literature to a possible connection between Robinson's work exploiting infinitesimals in applied mathematics, on the one hand, and his eventual development of a rigorous mathematical theory thereof, on the other?