The Harrah's logo was updated to the 4 point star in 1979. So these reel strips were changed sometime in 1979 or after and probably were used until Harrah's removed the mechanical machines by the late 1980's. When I worked at Harrah's Reno in the early 80's well over half the machines were still mechanical. It was said that Rome Andreotti (Harrah's gaming guru) did not like the Bally multiple coin machines, but finally succumbed to the fact that the Pace and Aristocrat mechanicals were harder to keep maintained and there was pressure from the new owners (Holiday Inns) to modernize the slots.