Re-instate the EGR blanking kit asap.
Re fuel consumption, have you recently checked that all brake pads are free in their callipers, also have you checked the handbrake shoes are correctly adjusted ie clear of the drums.

Thanks for the answers.
Following a day of working on the motor, I have checked out the following:
No brakes are binding and the callipers are free enough in their carriers.
The handbrake shoes are not binding, I had to adjust them up slightly after fitting new disks and handbrake shoes a couple of months ago.
Re-fitted the EGR blank and runs fine again.
Wheel alignment seem ok, no undue wear on the tyres.
Have resolved to a re-map from Pete Bell, an hours run from here and was satisfied with the re-map he did to our diesel P38.

Steve. 1968 Series IIA Pastel Green, nearly there project