On the weekly Adafruit Ask An Engineer show (the longest running electronics webshow) there is a call-in segment to claim a product they may be featuring or showing off that week. Your call is magically routed through and answered on their payphone but recently it was broken. They do have a replacement phone to fill in though. I don't think they were desperate to really turn on the Bat Signal but here in the spirit of open source is the Adafruit Batphone for your consideration.
Step 1: Get a Handle on Things First...Then You're Covered...
The Batphone is under a glass case. And if you have Alfred the Butler or Commissioner Gordon answering, you need the luxe version with a fancy handle on the top.
You could get an expensive knob or fancy window drapery pole finial that might do the trick but it is easy enough and more fun to put one together from miscellaneous parts.
I've got a few wooden beads and wooden doll parts. Add a dowel or pencil stub as the crossbar. Btw, the last time I went to IKEA, the remodeled store seems to have deprecated those handy mini pencils and paper tape measures. And a small plastic dish for the bell shaped handle bottom. Gestalt!
Glue all of your parts together to complete the handle structure.
Since the handle will be lifting some weight, I ensured the wood part was mechanically fastened to the plastic dish by screwing it in with some washers. I did use E6000 glue to attach it but was worried that the solvent glue may not be good with that plastic.
I found a plastic cake container/cover/carry case to use. The telephone was a bit too large to fit inside but I could remedy that by fitting a new rim on the bottom or or extending the top or lowering a section in the bottom, etc... It was cheap, so roll with what you can get.
Step 2: The Prime Directive...
I cut the corners on a block of scrap wood to fit in the bottom of the plastic dish. I could use that to attach the screws coming from the bigger cake case cover on the bottom. I used E6000 to glue the wood block in but found later that the plastic dish in the area of the ends of the wooden block had softened. I surmise it was the blob of glue that pooled up in the joint and the solvent vapors couldn't escape from the crevice attacking the plastic. When whatever glue left was cured, I filled the gap with regular craft glue to reinforce the spot.
Water-based paints do not like to stick to slick surfaces and I was going to use a water-based acrylic paint to cover it all.
You can either make the existing surface rough to better accept the paint or give it a coating that the paint can adhere to.
Cosplayers will use something like Plasti-Dip® to coat but that is expensive, pretty messy and nasty fumey. I could have built up several coats of regular glue but I just applied some paintable acrylic/silicone caulk to the surface. I had a half used tube nearby from other household repair tasks. Use a little bit of water on your fingers to smooth out the final surface. You can also use heavy-body thick acrylic gesso for priming artist paint canvases to do the job. Household latex paint primers would also work but you want something a bit thicker to fill out any surface imperfections or joints and give it a homogenous surface texture. Oh, I can also recommend using the new water-based white latex roof repair coatings/patching compounds which come in gallon size quantities if you want an industrial strength primer.
Prime and paint. Make it so.
When dry, you can add the Montblanc finishing touch on the cap, wait, an Adafruit logo printed out and decoupaged with glue, cut slices to have it better conform to the curved top.
Step 3: One Ringey Dingey...
You can still find standard rotary phones on the market today. This phone is a classic model in red color. I didn't want to mod the vintage phone too much so the only thing I did was to recreate the telephone dial label. I used a manual typewriter style font, cut out the paper print circle and dipped it in my tea for stain to give it an aged look.
I could have made a face plate/cover for the rotary dial to convert it into the single button direct line emergency use phone like the Batphone but I wanted to retain the rotary dial. Besides, it is fun to dial since it has so much tactile feel and sounds to it.
The light up effects are provided by an Adafruit Circuit Playground Classic.
Arduino programming flashes a short strip of 10 Neopixels attached to the board. The strip is mounted to a piece of cardboard to shape the strip which fits under the phone. The light is diffused by the bottom cake pan/plate to make it seem like the whole phone is lit up. The actual telephone case is of some opaque plastic so it would have been difficult to light it up from the inside of the phone. Someone could mold and cast a better shell of a more transluscent material if you wanted to really light it up from the inside.
Since there is a built-in microphone on the Circuit Playground, you could modify the demo sound level meter sketch to respond to the actual ringing of the phone or the conversation on the phone.
You would probably want to be more advanced to hack a method to directly wire up the phone as input for the board. Telephone analog audio and higher voltage ringer signals can damage your low voltage digital microcontroller board.