Today I got my 18 cleaned and tested injectors back from Nottingham Diesel Services Ltd.
The 6 NOS:2 x DL0 20D - release at 37 bar, good jet, no drips
3 x DL0 20D - release at 35 bar, good jet, no drips
1 x DL0 20B - release at 33 bar, good jet, no drips
The 4 originals from my car's engine:1 x DL0 20B - release at 29 bar, good jet, no drips
3 x DL0 20B - release at 27 bar, good jet, no drips
Random spare injectors: 3 x DL0 20B - release at 30-32 bar, good jet, small drip but OK
3 x DL0 20B - release at 22-25 bar, jet OK, but drips under residual pressure that could make cold and warm starting a problem.
2 x DL0 20B - defective
I'm going to use 4 x NOS injectors (DL0 20D).