No wonder I couldn't find it. I thought it was an i, and the N was just the prefix to the serial number

Some of the manufacturers had fairly crook ways of numbering their radios and others had a fairly orderly way of doing it. Healing was one good example of bad numbering. They had at least two radios with the model number "401". One was the popular midget mantel radio, a four valver that came in about a dozen colours, the other was a larger table model available in brown only. Two very different radios but the difference was the suffix letter in the model number, one radio was the 401A and the other the 401E.

Sometimes, a lot of research is needed to be able to trace some of the weird schemes employed.

The "N" on the label does look like it is meant to signify (serial) number. Maybe I am barking up the wrong tree here thinking the "N" is a cabinet style.

I'm pretty sure the schematic called 520-1 in volume 2 of the AORSM is the right one for this radio.

So what is the right designation? 520I (cabinet style I), or 520-1N?

In More Golden Age of Radio by John Stokes, there's a photo of an STC 'Police Radio Receiver' with a very similar case, and the same style of speaker fretwork. No model or date information is given.

a couple of the valves have gone,

They all seem to be there. Or do you mean they've gone bad? How would you know?

All the valves are there, but I was told by an old guy at the pub (not always the best resource) that if they are all black then they are likely to be blown, so based on that I think only 2 of them are any good.

I can only find 520A and 520B on this list, which looks pretty comprehensive.

http://www.hws.org.au/RadioHistory/manufacturers/STC.htm

I was told by an old guy at the pub (not always the best resource) that if they are all black then they are likely to be blown

Typical pub talk. Valves of that era can have a silvery or black coating on the inside of the glass envelope as part of the manufacturing process.

They cannot be written of as bad until they are tested.

Thanks for that. I haven't thrown anything out at this stage, just carefully removed them, blew as much dust out of the unit as I could and put them back in again.

...that if they are all black then they are likely to be blown, so based on that I think only 2 of them are any good.

Not always. One of the more popular power amplifier valves, the 6V6G, had a black coating over most of the inside of the envelope. There were other valves that did too. Some valves have a chrome look to them and this is the deposit that the 'getter' places on the glass when it is 'popped' during manufacture. The getter helps rid the inside of the valve of any remaining oxygen that would shorten the life of the filaments.

It is sometimes said that the valves are the strongest components in a radio, in an electronic sense and I think this is true. When a valve goes pop it is often caused by one of the other components rather than the valve just self-destructing. Valves that are 50 years old often still work perfectly.

Would itneffect the value at all if I stripped back and recoated the cabinet?
If not, are there any recommendations or is it simply a matter of sanding it back and repainting with laquer/paint?

I can only find 520A and 520B on this list, which looks pretty comprehensive.

That list is very useful, but it's not 100% comprehensive for all brands, or maybe for any one brand.

It was compiled from various sources such as trade journals and books of schematics that have survived. Documentation of some brands is very thin on the ground, while documentation for others is plentiful by comparison.

As has been mentioned, radio manufacturers often used the same chassis for various models for a period. A bit like the "face lift" approach used by car manufacturers today.

In technical terms, for restoration purposes, identifying the chassis is usually the key task.

As regards restoring the cabinet, member Vintage Pete is the man. He has posted a great deal of information on that subject in the Cabinet Repairs section.

Thanks guys. I am glad I found this group. Not being able to find much information made me a little apprehensive about working in it. I didn't want to find out that I had ruined a one of a kind museum piece.

CompleteNovice, could I strongly recommend you read Pete's recent posts on this site about cabinet restoration?

This guy really knows his stuff. I wish I'd met him before I did my AWA TV cabinet, I would have saved a lot of effort and got a better result. I rationalise the result of my efforts by saying that, when this TV was made, there was huge pressure to get sets out the door and so there wasn't time to do grain filling on the sides...(this is actually true, but who's going to believe that?!)

As far as affecting the value is concerned, any cabinet refinishing that is not authentic or perfectly done will detract from the value of the radio. Unless you plan to put in the work and get it right, don't even start. It's got to look either 70 years old with age-appropriate patina, or if not, like it just came off the production line 70 years ago.