76 Plymouth Valiant won't start

Well now my daughter tells me the odometer still works so it must be something in the dash for the speedo problem...

Could be you just need to pull the cable, slide it out of the casing and clean it. Lube with powered graphite and reinstall.

Also, the fuel gauge has never worked; Is it the float in the gas tank? I don't see that getting fixed in the near future...

Could be as simple as the wire off of the sender in the back or the jumper is missing.

Need to find the other issue first and get it running.