Named and painted by Ernest Lovato as a tribute to his wife's Irish heritage. This extraordinary image depicted the traditional Irish cudgel with some dainty wings attached together with a decorative title. As if this was not noticeable enough, the main tyres were given a white-wall finish to ensure the plane stood out across the airfield and could easily be seen in the air on arrival back from a mission. It is thought to be the only B17 in the ETO to have been given the white-wall tyres.
In the original version the name was spelt the Irish way (Shillelagh) but no-one could pronounce it so Lovato amended it to an Americanised version.