Thomas Strong Seccombe, the illustrator of Benny's caricatures, was an officer in the Royal Artillery - commissioned as Lieutenant 21st June 1856 promoted Captain 3rd April 1867 promoted Major 21st August 1875
Not a very distinguished career apparently so just as well he had his drawing ability to fall back on. I have just followed Mikes' link and there are several copies of the book available, as indeed, are individual prints but the latter at £85 are a tad pricey. The individual prints are all dated 1873.
As Mike says there are 26 prints in the series and I doubt that any/many were directed at a given individual and I say this just by looking at them.
Stuart