Thank you gentlemen for the answers.

The second curry coloured 600 arrived today, near mint, it has just been restrung and sits next to the grey/beige 505. I pickedthat up on Sunday (from the Acton factory where Montagu Napier built Britain's first racing cars and the engine that John Cobb used to set the outright lap record at Brooklands,) with a very tatty case and the wrong speaker. The one from the 400 which was very bad had to be jigged to sound right then glued to replace it. It looks and sounds fine now and cost me £15.

Curry number one was subjected to a good sorting out. The VDR in the agc circuit was replaced from the spares set and then realigned using a Marconi 2024 sig gen and an Agilent 5012 'scope, both of which make the job a breeze. Unfortunately, following a couple of hours on the bench, it has been permanently withdrawn from the collection because it is a perfect match for the newly redecorated bedroom's curtains. Resistance being futile, I had to buy the other one. That short wave set is now the grail for me. It goes all the way up to 108. Thank you for showing the picture.

I would like to see the fm section of the circuit diagram if you have it, please, Marc because it would be interesting to see what was done to stretch the band by 4 MHz. The tunerhead parts list could give me the clues to built a 108MHz hot rod out of one of the spares sets. Machining off the paint from the tuning scale and replacing it with a new scale might be an interesting thing to do. I'm investigating the purchase of some Nextel at the moment. Red, white and black at first. Can't find violet but blue, and grey beige are available.

I'm also considering making an injection moulding tool to make a similar (Not identical; I don't want to be accused of passing off or counterfeiting,) slider knob. That will take a bit of research.

Currently for sale on BidorBuy a very rare Beolit 600 dual SW ! Don't let pass this unique chance to get this beautiful radio. 🙂