Hugo
As you have replaced both discs and pads, this may be worth considering.
I had the same on my +8, I investigated very carefully and the conclusion I came to was it was a sticking piston on one calliper.
To check, jack the car up on level ground, put stands under chassis and then remove front wheels. Get a solid metal object and position next to the disc, fix a sharp pointed metal object to it (like a long nail) so that it is just touching the disc near the outer edge. Slowly rotate the disc and watch/listen for any run out of the disc, you can expect a few thousands of and inch, check both sides of the disc. Repeat for both discs. If you have minimal run out then it is unlikely to be the discs causing the issue. I discussed this issue with Peter Mulberry and the callipers on earlier cars can distort and cause one piston to stick and then you get uneven pad pressure causing the judder under low to medium pressure. If you do not get the judder if you brake hard then you are probably force freeing the sticking piston when so doing. I do not know it the later callipers fitted to Morgans are prone to this or not.
If you do not do many miles in the car then with it standing around one piston may be corroding and thus sticking. You may need to remove the calipers and inspect the pistons and barrels, or get someone to do this for you if you are confident in the discs.
With mine I replaced the callipers, and problem was solved, did this as my issue was due to distortion of the calliper body.
I hope this helps, or gives you some ideas of what to look for.
