I picked up some trade paperwork for Mainline trains along with some other Palitoy trade literature from eBay.
Toy trains aren't my thing, but from what I can find online this is the pre-launch trade catalogue and the very first Mainline price list, issued to retailers ahead of the launch.
If it was Action Man, it would be very collectable, but from what I can see on eBay, Mainline doesn't seem to be so sought-after. However, I've not been able to find any other examples of this preview trade catalogue and early price list sold, so I don't know if it's valuable or not. Are there any Mainline train enthusiasts who could advise?