Jim, recapping what many have said, fuse 7 powers:
the dash gauges (fuel and temp through the voltage regulator)
reverse light
windscreen motor
choke warning light
tach sensing
The fuel pump is NOT fused.
If I were you, I would purchase a volt-ohm meter (it is cheap), disconnect the battery negative lead, pull fuse 7 and measure the resistance from the green side to ground with all dash switches off. If shorted (very low resistance), there is a wiring short. Disconnect the green wires from fuse 7 until it disappears. If no short, turn on the above devices one at a time and shift transmission to reverse. Switch on the wiper motor last because it may cause a very low resistance measurement even with when OK. Either of the light bulbs will lower the reading to a few ohms; this is normal. I think Robert's assessment is quite likely correct.
You did not mention how quickly the fuse blows. A short is almost instantaneous, several seconds or longer is an overload, suspect wiper motor. Note, I am using schematics for '68 but think they are identical to yours in this area. Good luck.