This gives you the dimensions of the turbine inlet flange, which is where the T2, T3 etc comes from

https://www.sincocustoms.com/identifing-turbo-flanges/

You could probably contact a turbo specialist, and they could..might be able to fit a new core to your existing housings, that would be more modern and better than the old unit.
They'd be more familiar with what might interchange, or what turbine wheels etc might fit into your existing turbine housing