External French Doors (Rebated) - Lock options

Hi, I'm fitting a pair of hardwood exterior french doors - 'georgian' i.e. with small glass panels.

The doors are 44mm think, each door is rebated by 12mm (hence 2 x 22mm 'faces' on each door edge). Doors will open inwards.

I know I can use a standard sashlock with a rebate kit (and maybe a dummy handle on slave door for aesthetics), but I'm struggling with how to secure the slave door.

As I only have 2 x 22mm faces on the rebated door edge, I don't think I can use a flush bolt on the edge of door which would have been my preference - I can't see any flush bolts available narrower than 16mm and I think this would compromise the timber at edge?
I'm reluctant to use flush bolt on the interior door face which I think look fine but are not too secure given a single small glass pane could be broken to unlock, and I'm reluctant to use old-style rack bolts which also aren't very secure given they use a generic fluted key.

Any suggestions appreciated!?