Brian, I got
Douglas Crematorium Index and MI's
Also got Douglas Borough MIs that go with the Burial Registers you noted.
Book One Blocks A B C D E
Book TwoG H K L M N
Book Three P PX NA NB NC ND NE NF
Book Four NG NH NI NJ NK NL NM NN
Book Five NO NP NQ NR NS NT NU NV OA OB