When to glue a check in the body?

I have a cypress body, the top horn of which has a pretty good check in it. I've done the routing, but not sanding, roundover, contours, etc.

https://lh6.googleusercontent.com/-af9ghqsc0iQ/T4GKWEUk_KI/AAAAAAAACWc/t_FrL4aDjl4/s640/DSC_0013.jpg

https://lh4.googleusercontent.com/-wpq4egK56P0/T4GKVuPYg0I/AAAAAAAACWY/KNOo4ZnDMKg/s640/DSC_0008.jpg

I'm thinking I'll wick some water-thin CA into the crack, but I'm wondering about the best time to do it: before or after sanding/contouring?

I think before. Essentially, you just want to fill it and stabilize it so there's no chance of it worsening. Then you can sand and finish over it along with the rest of the body, hopefully minimizing the extent to which it shows.

Are you giving it a clear finish? I'd use epoxy in the check but that'll show under a clear coat, though most solutions will be evident. However if it's getting a colour finish, no problem.

Color finish (white's a color, right?). I'm hesitating to do it because I think it'll make that area considerably harder than the surrounding cypress, and it'll be trickier to sand it evenly. It also seems to be too narrow a crack to get epoxy in it. What I'm thinking right now is to sand my edges smooth first, then wick the CA in before the roundover/contouring.

Are you giving it a clear finish? I'd use epoxy in the check but that'll show under a clear coat, though most solutions will be evident. However if it's getting a colour finish, no problem.

Same here. Epoxy that you heat up so it gets in as deep as possible.