Thanks for the info on the usefulness of seat springs; first time working with them. Part of me wants to save them as I invested time into de-rusting them. However, it did not take much to push me off of the idea of saving them intact as it makes for much easier project! Lazy side wins!
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Cutting out the seat platformSome pictures from cutting out the seat platform out of 3/4" plywood. (I measured and cut the rectangle than laid the spring base over the top and traced additional cuts).
Base after cutting the rear of the seat NOTE: I did not cut the round corners out of the front until I attached the sub-floor to the seat base (see next post on what and why sub-floor).
Passenger Side's back corner ,
Zoom ,
Full Side ,
Front Corner Driver Side's ,
Front Corner 
