I'll take some better pictures of it at home, but here's how I mounted my Nashbar bag to the front rack.
You can't really tell, but the top of the bag now comes up to the level of the bars; perfect for viewing the map case on the top of the bag. I use a bungee attached to the shoulder strap loops to fasten the bag to the front rack. The "decaleur" is a $0.68 joiner plate from Home Depot. I bent it around a piece of PVC, and held it in place with deck screws. The handlebar mount from the bag is attached to the PVC, and the whole deal is held to the front rack with some #6 machine screws.
To avoid problems with my light (shadows from the bag, etc.) I unscrewed the light head from the regular L&M mount and built cut an extender tab from another joiner plate. I mounted that to the front of the platform rack so my light sits out front of the bag and just above my front wheel.
It may be a completely MacGuyvered solution, but for now it's cheaper than a $60 chromed decaleur and $110 Ostrich bag.