Yes, Norman Hyde:
Full kit quite pricey, but they sell without caliper, I imagine they‘ll sell the disc only if asked.
Is it for road or race Chris? I don’t know of any bigger discs for Triumphs that would be eligible for classes racing.
I’ve got a spare Hyde adapter, to bolt to Triumph disc forks and take an AP caliper for their bigger disc, that you can have if you want it.