We are in the middle of a frame-off rebuild of our 1974 Hunter I. I traded a couple of old pickup cabs for the steel and welding needed. The spare is now mounted just in front of the body, and there's a hitch receiver just under it so we can carry our bike rack between the body and our car (and remove it so we can use it directly on the car!)
You can see the new 2" square steel extends from the cross-member at the axle's front spring attachment to the original 2" square tongue steel - about 5' long. The center front cross-member was also replaced by 2" square steel so it's strong enough to support the spare tire and bike rack.
Here's the frame, just painted:
You can email me if you have questions!
tericson <at that> yahoo (COMmerical)