My error in naming them “Vipers”. They were definitely the Sutton cobalts, purple boxed set SM2. Fortunately I didn’t purchase them; I ordered them for my workshop. The bits were blunted by (again) over-zealous Marine Techs who thankfully stopped at two before calling me in to de-fornicate their errors.
Interestingly; I just found a Sutton “press release” from 2016 where they were spruiking that their HSS now came from Europe….
Independent testing shows Sutton Tools’ Viper Plus and INOX drill bits are class leaders | Sutton Tools My comparison definitely pre-dates this by a decade.