My wish list would include 5021. It would be great to have a 3 cylinder locomotive running around just to listen to. I know, shays are 3 cylinder but a rod engine develops a lopeing(sp?)exhaust that is unique. It's a shame the all that work was put into the 5021 back in the '60's only to have the locomotive placed back on display after running back and forth a couple hundred yards. I chased the 4472(not a GS) Flying Scotsman on the WP in when she visited the Bay Area a was treated to the unique 3 cylinder exhaust. Incidentally, the Brits have just constructed a BRAND NEW A1 class, 3 cylinder pacific and are running it through trials. They have a great website. Just do a search on A1 steam locomotive.