Fire is well gone at this stage. What's wrong with it?
You may get one used on fleebay, but do you want fit a used unit? I wouldn't!
I would say it's time for "your fire/boiler has had had it mrs!"
Early to Mid 90s unit, depending what is wrong you may still get some parts (give Baxi a call) as for replacing the complete fire if you could get one , it would be well over £600