Hi Felch

Lovely effort. would have given a good experience to you. I am a retired telecom engineer with Telephone instrument repaig experience. Thus i really liked your project.

as you know, the rotary dials have oulived-

perhaps realising DTMF dialing function, retreving the caller ID thro DTMF and FSK modes and try to store incoming and utgoing call records with perhaps small sd memory card interface,EMERGENCY LINE DIALING UNDER ROBBERY OR CALAMITY AUTOMATICALLY etc, leaving the speech functions to the dedicated chips.
I know, rather a large project.--

takes time -- but a good experience of realtime project

Congrats Felch, for what you have achieved

All the best