I also noticed that thing about lead being used to check the gear mesh. Lead hasn't been used for that for at least a couple of decades. Titanium dioxide has been common for a long time. You can't even buy the lead compound for rolling a pattern on a diff anymore. Blackstone needs to revise their comments.
I do believe that Ford has no maintenance interval for changing the manual trans fluid in our cars. I still change it anyway because I want it to last a long time.
