Early transparent telephones
 

Can anyone shed some light on the clear transparent 300 series telephones, not sure if this is the right place to ask as I’d love one, thanks in advance ???

Re: Early transparent telephones
 

I can't say for the 300 series (a bit before my time), but I saw - and used - a transparent 700 series (I think it was a 706). It was a sales demonstrator which was shown at public promotional events. Perhaps the transparent 300 series was the same? Under any circumstance, I guess they would be super-rare and very collectable.

As I was working for GPO telephones at the time, I asked if they might be available to the public. The answer was a definite NO. They were specials for demonstration use only...