Corsair,
What I do to map the MONON on routeslip is luckily they still have the railroad markings on the map. For areas that weren't rails converted to trails, I use the hybrid function with the satellite images and try to adjust best as I'm able. I can't help with the Mozilla functions, but if you go to report a bug, the owner is real good about responding with a suggestion if possible.
Good Luck,
Mary

BTW, I'm still trying to enter my century route, but I finally got the breakfast ride which is the middle part of my century entered. http://www.routeslip.com/map.php?map=980