A Slight change of mind with major consequences

Ok, so I thought everything was going along all nice and fine. The layout was coming together well, both parts had been exported to Trainz but, then the fun started. On trying to merge the two routes I found out that some of the maps would be missing. Might not sound like an issue but there was all of a sudden no maps/plans of my home town which to me seemed to defeat the whole exercise. Any way, I've decided to really push my computer to the limit, hope this works, but I'm going to create the layout as 1 part i.e. no route merging. At the same time I'm going to extend the scope of the area covered to include Barnsley in the NW quadrant and Worksop in the SW quadrant. A lot more work is therefore involved but I suppose it will give me a more complete area operationally.