After paying more attention to Randy's guitar sound on a couple live shows I have found that he used the wah far more frequently live than I ever heard or noticed before.
Attached is the first example for you to hear what I am talking about it..
Children of the Grave from the Blizzard of Ozz Live! album (30 years after)
Markers to listen for..
1:41 - Wah Enable
1:48 - Wah Off
2:07 - Wah Enable
2:27- Wah Off (possibly off at 2:50 instead as couple chords sound like the wah might be still enabled)
3:19 - Wah Enabled
3:41 - Wah Off (thicker solo sound throughout)
There is a chance that he never shut the wah off from 3:19 onward. Here he may have just cocked the wah back a little to thicken it up, then at 4:10 he slams it closed again to accent the A chord.
4:10 - Wah Enabled until end (really accented this note)
Headphones recommended but I noticed all this stuff in my car the other day which is what led me down this path

Let me know if any of this is of interest and ill do a couple more when I have a chance.