performance pro CLM18VRB transplanted internals from a ryobi battery?

On an older thread about the old B+Q CLM18VRB battery, someone says they managed to transplant the equivalent Ryobi battery internals into the old casing. They said they had to swap the terminals over as the Ryobi battery contacts are the other way round.
I was wondering what the equivalent battery is and if someone can confirm the swap. It would be good as the drill itself is still working fine, I just need another battery.

Many thanks in advance