I like that idea Karen, and your implementation. My stepfather (86) cannot get to grips with modern appliances and would love something similar.
Sue - I don't know about Australia but you can still buy basic mobile phones new in the UK. They're usually marketed as rugged devices for use in harsh environments. The following link is an example not a recommendation.
https://cpc.farnell.com/c/computer-o.../mobile-phones