Robert, 

They are identical EXCEPT the new class may have one...two...three...etc new / additional  properties / fields.

Robert,

We learned that when we were doing proof of concept on the idea of pointing an older class to the new classes data storage.

And I don't think locking is an issue, at least in my testing, because I was doing my testing on a local laptop install of IRIS so there was no contention with another process opening or changing the data.

Luis, Thanks,  How does one go about loading a persistent object's stream data into a dynamic object?