As for the differences in the SE4s... the differences are the fact that the firebox on the "American" one has 6 holes, whereas the "English" one has 4 holes. The flywheel is grooved on one, and not the other, the chimney is in a slightly different position (it's closer to the boiler end on the 'English' one). Also, the most major difference, is the fact the one which I bought from the other side of the water has smaller, shorter, cast cylingers which I have never ever seen before.
I am so annoyed - I just went and set all the SE4s out on the worktop, and then I even went outside and got an oil can off the back of the International tractor in the rain after I had just had a bath and got all warm... and then I find (or not, as the case may be!) that I have lost my camera somehow!!! So now I can't even film them
Ohhh well, I'll steam them another day!