12 down: Loco inventor pilloried photographer beyond measure (10)
Excellent definition, excellent use of pilloried: pilloried photographer beyond measure = HENSON beyond STEP = STEPHENSON = loco (locomotive) inventor.
7 down: Macabre author of Kama Sutra? (9)
I knew the author and I chuckled: of Kama Sutra = LOVE CRAFT = LOVECRAFT = macabre author.
13 across: Cockney journo dispatched soundly to grave, perhaps (6)
Ridiculously good combination of brilliance: Cockney journo dispatched soundly = Cockney HACK SENT soundly = ACK SENT soundly = ACCENT = grave, perhaps.