I used New, Reconditioned & Remanufactured & Turbo Rebuild Parts, they said its hit and miss if the parts are available for some standard turbos but its not also out there hands to make some bits up if needs be, they were able to hybrid a CT12 I had
Pretty sure Midland Turbos can help with modifying Toyota turbo's Turbo Reconditioning - Reconditioned Turbos - Turbochargers UK | Midland Turbo