Fuel leak found and fixed. waiting for RTV to set before I re test and put the tank back up.
mouse nest between the body and the fuel tank, mouse chewed through one of two fuel vent lines that run from the top of the tank to the fuel filler neck. No way to get the tank all the way out without dropping the beam. Just enough clearance to work above the tank with shocks pulled and tire removed and tank tipped towards the rear. Patched the plastic line with 1/4" fuel injection line, brass nipples, and adhesive shrink tube to up-size the 1/4 barbs to the plastic line. coated the outside of the adhesive shrink with black RTV and hose clamps. It's a vent line, so no pressure, but I'll see if it deals OK with intermittent diesel contact every time the tank is filled full 🤞🏻
Otherwise I'll have to get a factory replacement line and cut the stainless steel keepers at the filler neck and at the tank.