Greetings! Can someone help me/ my hookahs??

[Sierram94]

I bought two hookahs from a veteran who said she bought them in Qatar. They looked beautiful in the pics and she said I’d need to buy pieces but, she was selling them so cheap. To me it was a steal but, I’m not sure if they’re still usable after looking in the pipes and seeing white hard build up in the stem. 
Is there anything I can use to clean the pipes? Do anyone know what the missing piece (that the rubber bowl grommet goes on) is called? Thank you in advance. My pics won’t upload.