The roof end is a curved shape whereas on the Amati it is a straight line. However this can be made the correct shape by just forming a wood part for that last section. There is a step on this portion at least on pre WW2 units, which tends to hide this but you can see the curve very neatly. We in Europe knew these cars when they were still running and remember the curve because at that time that step had been removed as well as the end ladders.
Of course this kit could also be used to make a finely detailed interior for a J&M car (although the thickness of the doors for instance is too great). But that would put that car at a formidable price wouldn't it...
But don't get me wrong I certainly didn't want to ruin yours or anybodies pleasure in buying this kit. I just feel that for me who is familiar with these for having seen them a good deal, I felt it would be my duty to warn people from oversea about these discrepancies. It probably can be made into an operating unit.