At first glance, the two Mogambo daybills and one sheets look similar but when you take a closer look there are some differences in the artwork and wording that clearly show that the posters pictured on the right are both reissues. The reissue one sheet and daybill both have the words "A Materpiece Reprint" which indicates that the posters were for the re release of the film.
That just leaves the question of when they were reissued. The original daybill is printed by W.E.Smith which is correct for a 1953 release while the reissue was printed by A and C printers who only printed for a short time during 1960 and 1962 so the reissues can confidently be described as early 60s releases. The one sheets do not have printers details but it is likely that their release date corresponds with the daybills.
On a Kenyan safari, white hunter Victor Marswell has a love triangle with seductive American socialite Eloise Kelly and anthropologist Donald Nordley's cheating wife Linda.