10/28/1988 Disneyland Line:
Click picture to enlarge
This article from the Disneyland Line employee newsletter was a bit optimistic. Splash Mountain ended up starting employee testing in May 1989 after the original logs were chopped to bits and replaced. The replacement logs seated 7 and were slightly shorter.
The grand opening was 7/17/1989--about six months late.
Note the Drop 5 runout rails; originally the runout was designed to be adjustable to adjust the splash seasonally. That feature never came to be.
I wonder what the final Audio-Animatronic count was?