I know that fuel gauges and fuel senders must have matching resistance, The '59 gauge takes a 30 ohm sender. No telling what the resistance is on the Jeep sender. The chances of them working together is very low.

Solving that one could be as easy as buying an aftermarket 30 ohm sender for the tank or maybe not.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.