ChristiaanJ
Both A/C 214 (OAG) and 216 (OAF) were Variant 192 A/C (British Unsold A/C). 216 was later converted to a 102 (British Airways) Variant, where 214 more or less stayed as a Variant 192. I'm not disputing what you say about possible APU mountings (I guess it would HAVE to be at the front section of the lower cargo hold somewhere) but I for one have certainly never seen any evidence of them. I'm still trying to imagine where the air inlet and exhausts would have to be arranged, not to mention pneumatic services ducting/hydraulics. Wouldn't it be interesting to find out?