I think you have made an excellent job of it and I like the standard wheels. I went through exactly the same sort of issues when I built the racing Group 4 Martini Version. My only comment would be to see if you could widen the track of the wheels. I substituted the kit axles with some wider ones of my own, a simple but effective fix.
You may have seen my racing version
http://www.automotiveforums.com/vbul...d.php?t=912600
Including Zoom Zoom's very nicely built version that makes a total of only 3 built versions I have seen of Monogram Porsche 924's! My brother is also in the process of building one which had a broken a pillar and was also badly squashed in the box, so it may soon be 4!