Track git blame through two unrelated histories

Hello!

I have a weird use case. A repository at my company was migrated git -> non-git vcs -> git again.

During transition to non-git vcs the history was lost, i.e. an initial commit was created from some known commit from the old git repo.

Migration to new git repo was more transparent and we have the whole history.

So let's say I add two remotes and fetch all the commits, but they look like this:

A->B-> .... . . . -> Z    history1

1 -> 2 -> ..... -> 0 history2

and file contents in commits Z and 1 are exactly the same, but the commits themselves are completely unrelated for git.

What I want to achieve is blame working across this boundary.

What can I do? It this possible right now? Is it difficult to implement? Is there a good enough workaround? I don't think rewriting commits 1... 0 is an option, but rewriting A ... Z is an option.

What do you think?