Hi Haldi,
I'm not sure if it's a different book but I have Lynette Baxter's "Balti - The Complete Cookbook" (ISBN 1-85605-246-x). Lynette Baxter is apparently a home economics graduate and works on (or did work on) product and recipe development for high street retailers.
It is easy to spot many similarities (i.e. wads of similar text) between it, Pat Chapman's books, and the "100 Best Baltis" book (all published around the same time and this and the "100 Best Baltis" following on the heels of Pat Chapman's earlier books I believe). They seem to have often used the same reference source (or each other's books of course).
This spice mix is, as near as damn it, the same as that in the 100 Best Baltis Cookbook (except for using a little more salt, cumin and chilli).
Yes, it uses a "balti sauce" (and has a recipe for a "quick balti sauce", just like 100 Best Baltis), together with this "balti spice mix" and a "balti garam masala".
I've made the balti base (and used several of her recipes) and am not overly impressed with it.
Nevertheless, like the other books, this book is also a useful reference and is worth having.
PS: I can't understand how a "spice mix" cannot have tumeric in it. Those deep yellow stains are, to me anyway, a clear indication of a genuine BIR curry (every bit as much so as "the BIR smell" and "the BIR taste"!)! ;D