We used testers for every level, and the game has been completed by others. It's been a while but I had a look for you - when the level starts, I believe it's possible to stand at the left side in an precise position and not be hit by the train which will turn around and you can follow it, and then jump over it to collect the item.
ok, I checked it. At the start of the level, move to the left and hide at the edge. The train will approach and turn away. Now follow the train until you reach the middle of the screen. When the train comes back, jump up, without moving forward - just a straight jump up. If you time it correctly, the train will go under you and you will not be hit. Now go and collect the item. Wait here for the train to return, it will not hit you in the far corner. Follow the train again and use the same trick, jump straight up and not forward, and you will get past it.
I made it at last! Thank you for wasting your time on this. The crucial point was the precise position you have to have at the left side when the level begins. I had not realised that one does not only have to drag Willy to the left, but as soon as he reaches the wall, to give him an instantaneous move on the right, so that he faces the train. This trick makes him hide from it. 38 years of paying Manic Miner and it's now that I realised that point. Thanks again!