We have a vintage rotary phone from the 1940s that was rewired to the “modern” plug and play plug back in the '80s. We were able to use it with our landline – more as a novelty than anything, because the Bakelite handset was heavy as hell to hold to your ear for longer than a few minutes – until 2016 when my wife and kids finally made me get a smart phone and stop paying for a landline.
I recently bought a vintage mid-century Ericofon on eBay and an X-Link bluetooth adapter on Amazon that uses my cell phone to allow it to make calls. Again, a fun novelty.
