Hi Clive.
If you damage the mains transformer on this set it will be very difficult to replace it.
Are you going to attempt to repair this yourself?
If so don't do anything rash get or make yourself a lamp limiter
Read this:
http://www.vintage-radio.com/repair-...ing-power.html
Although you have had this running it was clearly faulty and you need to consider what you do before you replace the fuse.
You can get the circuit from the Radiomusem I already linked I think as a guest you can download 3 pages.
Next question can you read a circuit diagram?
Everyone here will pitch in to help but you need to do a bit of swotting to make it less frustrating for all.
Your going to need a multimeter.
And as Radio Wrangler has said No1 Eyeball and your Nose are a great start!
Cheers
Mike T