Thanks for the encouragement! I've inquired at Syntaur. Do you recall any details about what keybed the lighter springs were from, or their size or gauge? Any identifying info would be much appreciated.
BTW, in regards to the 73/76 key format, I do love that size. I really enjoy the weighted 76-key keyboard on my Kurzweil PC1SE, reportedly a Fatar TP/30 model. Same old issue, though, that keyboard is 20 lbs heavier than the Artis7...