Ceiling pattern issue

[Minna Reid]

I ripped half a ceiling in a rehab, and have now resheetrocked and need to finish. problem is the original half of the ceiling has a popcorn finish, but its got a swirly pattern to it. I need to have the whole ceiling match, obviously. Does anyone know of where I could find a tool to swirl popcorn ceiling paint...OR...does anyone have a better idea of how to match the whole ceiling?