73 duster ac vacuum questions

Hey guys so I'm trying to install an ac in my duster it's a factory ac car but the previous owners cut all the vacuum tubing at the firewall, I've looked at a few different manuals and I still can't figure it out. if any of y'all know the proper vacuum setup it would be greatly appreciated.
Currently all I have is the vacuum reservoir connected to the engine but after that I have no clue.