^Was gonna say the same. Seems like a leave it be or fix it right kinda thing.
Dunno how much OP plans on driving the truck but if it’s a knock around pasture wagon, leave it on one tank. If using it regularly and driving any real distances, double the fuel capacity is nice.
Regardless, you’re gonna want to get to the top of the tank and just replace the hoses/re route the 3 lines from there. At that point it’s easier with the bed off and with the bed off, it’s pretty inviting to fix it right the first time IMO. Thinking more long term.
Bypassing the selector valve for the gauge should also be done if you’re truly going to one tank permanently.
And if this is just. Stop gap then why spend any time at all if it’s been fine for 30 years.