Hi Dave, apologies for the delay in the response!
We can confirm there will be 7 volumes of Sinister Dexter.
Speculation time!
Volume 5 (200 pages):
...And Death have shall have no Dumb Minions - 55pp
Festive Spirits - 5pp
Malone - 35pp
Places to go, people to do - 30pp
Pros and Cons - 20pp
The Last Thing I do - 30pp
The Doctor Is In - 20pp
Normal Service - 5pp
Volume 6* (200 pages):
*All the stories hereon are drawn by Anthony Williams, which means they all blur together a bit in my mind. Maybe there's a few that aren't strictly necessary to the ongoing story and could be dropped?Life is an Open Casket - 30pp
Yer Ass from Yer Elbow - 10pp
The Bournemouth Identity - 20pp
Desperately Fleeing Ernest - 25pp
Wish U Were Here - 30pp
Rush from her with Love - 15pp
Watch with Motherfunter - 5pp
Better the Devil You Know - 25pp
The Why Shaped Cut - 30pp
Volume 7 (111 pages):
Are you Being Severed? - 30pp
Charon's Crossing - 25pp
Inverse Ninjas Rule - 6pp
The Dead-End Job - 24pp
Dirty Deeds done Cheap - 16pp
Now and Again - 10pp
And that's the end of War of the Moses. Obviously there's a bit of room in that last volume for more material, particularly if you bumped a few stories back into vol 6. If they do that, then they could just about squeeze in the next two mini-arcs
Witless Protection at 65 pages, and
The Generican Dream at 51.