Is there a matching boot mounted CD changer for the tape deck? That would be about right for the period, though a CD player in the front wouldn't be out of character. The CD should of course skip on every bump you drive over to be authentic
This would pass at a quick glance, but is rather costly. I just think I would get something half decent and pretend it has had an aftermarket setup for the last 19 years
https://www.carbuildersolutions.com/...sd-card-player
Edit: I think the classic way out of this is to use an FM transmitter so you put a bluetooth receiver into the antenna input. That way you can tune the radio to your modern source. Can mess up the radio reception though.
Another edit: This could be cheap enough to be in the "worth a punt" category:
https://www.amazon.co.uk/gp/product/B0713N33KS