Hi Peter I will explain. The early period of railway nationalisation, under the control of the British Transport Council, saw the large-scale regeneration of the railway network and the move towards modernisation and is recognised by use of the Lion and Wheel logo.
This appears to be the standard adopted by Bachmann and some stores for UK railway models, e.g. Hattons :- https://www.hattons.co.uk/newsdetail?id=799 Rails of Sheffield :- https://railsofsheffield.com/pages/what-do-all-the-icons-mean?_pos=20&_sid=3d3f3b0a4&_ss=r Jim
Right not a very good way to teach the history of rail. They must think most of their customers are not that bright.
They are there to sell us their merchandise, not educate us, and as one of them says it's a guide as many items last through multiple eras, e.g. in various liveries, modifications and eventually levels of decay Jim
P.S. I'm not that bright as I use the era numbers as a guide, mind you some stores are pretty dim when the eras applied are obviously very wrong! And don't get me going about the number of times I see second hand items incorrectly described as Ringfield or Scalextric type motors or factory weathered applied to wagons produced long before weathering was a rtr option...