Well I had to know so I did a temp patch back to the VDU manual values... (yes its messy):
anyway now I still get a composite image on the Phillips (as the Modulator is also in circuit I assume it drops the levels a bit) although it did blank on me once or twice. Inverse is still junk.
UHF is awful though
But, the Sony can now get a stable picture in both Graphics and Text - although you have to twiddle the horiz. hold every time you turn the MK14 on or off.
So for those who were observant on the rubbish picture above no surprises here:
https://www.youtube.com/watch?v=vtL2yKEOh74