uk region 2 hack for jap ps2

I have Jap PS2 SCPH 15000 with DVD driver v1.01.

Having obtained several UK DVDs, I can confirm that the dual shock button pressing trick described in this topic doesn't work - not even producing the DVD menu.

Regionless DVDs (including PAL) play ok on this PS2 without any tricks.

So that leaves us as follows:
1 Japan is Region 2 NTSC
2 UK is Region 2 PAL
3 How does one get a UK DVD working on this PS2?