Another option is a bluetooth adapter. It looks like a cigarette lighter USB charger, but it will connect with a bluetooth device and then sends an FM signal. You just tune the stock radio to the set frequency. Like this...
IMDEN Bluetooth 5.0 FM Transmitter for Car, 3.0 Wireless Bluetooth FM Radio Adapter Music Player FM Transmitter/Car Kit with Hands-Free Calling and 2 USB Ports Charger Support USB Drive
https://www.amazon.com/dp/B07F2RTN5Z/?tag=gbody-20
The sound quality is not absolutely stellar but it will pass. Another option is to find someone to put bluetooth in your stock radio. That's what I did with my 96
Roadmaster...
I don't know anything about this company, but just linking it to demonstrate that there are people out there doing this....
Another option is Retrosound. They likely have a shaft style radio that will fit your bezel without modification and has the bluetooth built in....
Modern Sound For Your Classic. The leading manufacturer of classic car stereos and audio equipment for the restoration marketplace.
www.retromanufacturing.com