Finally, I'm able to post images of the various prints I can supply, sorry for the delay!
Firstly there are prints from the Christmas issues of John O'London magazine between 1928 and 1933. 1928 is black and white, the others are in colour. Full size prints of these on 15" x 12" paper would be no more than £12 for each year. Identical advertisements also featured in 'The Humorist' and 'London Opinion' Christmas issues.

On the top row, from the left, the years are 1928, 1929 & 1930 and on the bottom row, 1931, 1932 & 1933.
Then there are three advertising leaflets. The originals are double sided and multi folded, and the images of the various portions have been flipped where necessary to create the composite images shown below. I don't have exact years for these but approximate dates (give or take a year) are shown. Full size prints of these, on 24" x 20" paper should be no more than £20 each. (The pictures below are not to scale)

Leaflet A is the largest at around 21" x 14". This shows that 'Jade green' (known to most of us as green measles), 'Lapis blue' (now known as blue measles) and 'Grey Jazz' were all colours 'officially named' by Conway Stewart. The date would be around 1930.
Leaflet B would date to around 1935.
The size is around 16" square.
Leaflet C is the same size as leaflet B and I think dates to around 1937. Some of you may already have prints from me of the lower part of the image, which will give you an idea of the size and quality generally.
I do also have a print of a later leaflet dating to 1939, which is especially interesting as it is overprinted with new prices from October 2nd showing the increases that were brought in soon after war was declared. Unfortunately, I don't own the original of this and I promised the owner that I wouldn't distribute copies - sorry folks!
If you want something to display, or to refer to regularly for research, you should consider buying prints. Though it is great to have the originals (and all my JoL advertisements are in context, as part of the complete magazine), they are not printed on great quality paper and are usually fragile or have been folded, so not ideal for display especially where sun may cause them to fade.
Actual price will depend on the total number of prints ordered for each image size, so if you tell your friends and increase the numbers, you should save money! Postage will be extra. I suggest that we let the order book run for around 4 weeks (I'll post a week's warning when we are about to close) and that anybody who wants to order should contact me by e-mail (click on my name in the contributors list at the start of the Blog to make contact if you haven't already got my e-mail address). When all the orders are in, I'll mail everybody individually to let them know the final total - and then I'll need to get all payments in before I actually place the order with the printers! Paypal will be OK and I'm happy to send prints anywhere in the world. It normally takes about 10 days to get the finished prints back from the laboratory, so if all goes according to plan, prints would be posted around the end of March.
As far as I know, there are no different coloured advertisements to be found in the Christmas issues of other years or in other magazines, though there was a full colour insert in the 'British Stationer' of November 1928 which I'd love to get hold of - if anybody has one of these to sell, please let me know! I'd also be delighted to hear about any colour advertising from the colonies - I have one nice advertisement from the Times of India from 1929 showing two great Dinkie sets, but there must presumably have been others in magazines from Australia, Canada, New Zealand or South Africa over the years. Similarly, I think there were probably other colour leaflets apart from the four mentioned above. please let us know if you have anything different!
Finally, please do not rob these images for your websites without asking first! The pictures above have been watermarked visibly (prints will not show the watermark) and electronically by Digimarc, so they are traceable.
Andy Russell