An ad on Facebook. You can customize the number and I knew immediately what mine had to be. Even though the phone in Ghostbusters isn't a black rotary dial, Jim Rockford's was.
I just got the Tandy calculator Egon wears in commercial. I don't have the black cover piece. What info do you maybe have. I need to make one. Hoping you have some good info: measurements and such if you have one.
You're not the first person to ask me for measurements of the interface. My friend James did years ago, and then I later saw his resulting build and it totally fooled me. I thought he'd sourced one, I had no idea it was handmade. Message me on Facebook and I'll link you to the pics. They're in an old album there called My Ghostbusters Fandom pt. 2.