V70 D5 185 swirl, DPF & oil leaks

[TurboDiesel2006]

My 2006 D5 185 manual said the DPF (soot filter) was full. This was unexpected as I had recently done several long journeys. I did a forced re-gen using VIDA which created a load of 'white' smoke but interestingly only revved up to 2000rpm and went on for an hour without shutting down properly. I cleared the code and all seemed well so perhaps that worked.
Fuel consumption has dropped from 51 to 44mpg.
At the same time the swirl flap linkage was off and there is a lot of oil around the swirl link area.
I have also noticed oil leaking from;
- the LHS (passenger UK car) of the engine around the brake vacuum/boost pump
- at the front of the engine where the pipe (water / oil) that goes over the rocker cover splits and goes to the oil filter/separator and somewhere else.
Oil consumption is also high at about a litre every 3 or 4 weeks and although there are the oil leaks noted above it is not dripping underneath the car to warrant that much consumption.
All of which makes me think the oil is leaking into into the intake system somewhere, being combusted then being captured by the DPF. I also wondered if this was also pressurising the crankcase which exacerbates the oil leaks.
I am fitting new swirl flaps, rocker cover gasket and linkage and new seals for the brake booster but I am not sure this is the full answer.
Does anybody have experience of this scenario and the likely remedy.