I only picked up sh3ditor about a week ago so I'm still green when it comes to most of the stuff.
By crew animations do you mean the animation that controls how the crew looks and operates the deck gun? When I get to that step I think it will be a matter of changing the animations of the 20mm and replace them with what the crew does on the 88.
Perhaps there were multiple ways of doing this. I got it to work:
https://imgur.com/a/DcBrhpD
The gun moves and looks just like the 88 on the bigger boats.
As for the thread regarding animations, I have looked at it before and could infer some of the information but the images show up as "Sorry, image is currently unavailable".