[chezet]

I have answers from Paul Hutton.  Tanks were painted, because the solder joints would not withstand the heat of stove enamelling.  Lines were gold leaf, but lettering was always transfers because hand-painting would have ben too slow and expensive.  Thank you, Paul.

[BobClark]

... it might be difficult to answer at all ...

Many thanks for your answer, Thomas.  It is well known that John Marston finished their bikes with stove enamelling - which was their core business before they went into bikes, but by the mid 1930s they may well have changed to ordinary paint - which would mean your bike could indeed have been that way when new. (Or not, of course, I'm admitting ignorance!) 

What I am really hoping for is responses from members who have unrestored flat-tankers, where the tank can be closely examined to find out if the finish is stove enamel or paint, and the lettering a transfer or hand-painted.  Anyone out there ...?

[Thomas]

Well, Bob, it might be difficult to answer at all, especially for rare bikes like your 1925 model. I have a 1937 Model 9 so that I cannot guarantee a correct reply for your machine. I am already surprised that the frame ("rest of the bike") should be stove enamelled. At least mine is simply painted as is my saddle tank. The lines are 22 carat gold leave, indeed. I don't know if this applies to the letters. There is a problem with transfers. They are printed onto a transparent carrier foil. To apply the transfer onto a painted tank you need to pr-sand its surface for a good connection. But then one can see to sanded surface under the carrier foil. For that reason a foiler who applies only the letters and nothing else is a choice. My gold lines have about 8mm width.
Cheers, Thomas

[BobClark]

Um.  Loads of people seem to have read this post but there isn't a single reply.  Is the reality that no-one actually knows the answers to what I am asking?

[BobClark]

I have a 1925 Model 6.  It's a long story not relevant here, but at present the bike is in the hands of a Sunbeam specialist for a full mechanical rebuild; after that I will handle more cosmetic issues such as paint and plate, and then final reassembly.

A question has arisen over the original finish of the petrol/oil tank. The specialist says that he thinks that at this period tanks were painted rather than stove-enamelled like the rest of the bike.  I simply don't know.  Can anyone cast light on this matter?

The specialist shares my understanding that the lines on the tank were hand-painted with gold leaf, but beyond this believes that the words "The Sunbeam" were hand-lettered and finished in gold leaf rather than being a gold-coloured transfer.  Again, I don't know, and am looking for solid information.  If anyone has this, I would also appreciate a template or dimensioned drawing for the lines and the exact location of the words.  I have access to an absolutely excellent professional signwriter who has done lots of classic vehicle work: he can do anything I ask but needs to be told exactly what the specification is.  FYI: https://www.rosshastiesigns.com .