Ok, I've got 1999 set up on my pi.
I already have river5 running on my Raspberry pi. Today I thought I'd try to get 1999 running too.
I followed the intructions ate 1999-project/setup.md at master · scripting/1999-project.
nodejs, nmp & nodejs-legacy were already installed. The rest of the install went exactly as the doc suggests.
I've got Dynamic DNS running so just opened up 1999 on my firewall in the bt hub settings.