Hi Guys, Well, I have done a bit of searching about. It does seem that there is less (racing) choice now for the old RD/TZ caliper. Of course, there is no doubt that a modern lightweight floating disc and a good multi piston caliper can offer great braking. However, I am sticking to my early RD/TZ parts as far as possible so, no intention to change the caliper/disc.
You might find some old racing pads out there. Maybe some old Ferodo or gen Yamaha TZ pads NOS. Also, looks like there is a Sumitomo version for the TZ. It is hard to find info about these old pads, even if you find someone advertising some.
One thing to remember, is that older type pads may have asbestos in them and, they will definitely be poor until fully heated, if they are old Road Racing pads. Even some modern Racing brake pads caution that they need warming-up.
However, I have looked at other pads and I think I have found a good option. There is a brake pads review on the old TZ Forum. The guys there were very complimentary about the SBS 504HF Ceramic pads. These are a road pad that work well from cold. They thing is, they got a good review for racing on a TZ750! opinion was, good from cold, good braking, didn't fade, kind on discs and lasted well! Remember, this is on a racing TZ using the same iron caliper. So, I think these sound a fair bet.
Oh Yes, £24 inc 1st class signed-for.

Cheers
5port