I'm sure most of you has seen the image below. These Billgrams have become a bedrock on which many TKs have been built.
However this image, and 1 very similar, has a colour on it no longer deemed correct. Rather than carrying on explaining it I've made a new diagram, sorry no catchy name this time, with just the correct colours.
The images show the Humbrol colours, but the Testors equivalents are shown too if that's easier to source.
All this was