Hello Jemma,
good to know this has been helpfull.
I think this is your best approach, load a history to CUBE 2.
Here you can do a copy or do a re-desing of CUBE 2 and after the load of history data you decide, you can check the result of the re-design. If it works fine then you can re-design cube 1 and let the delta continue.
Regards from MX.