A truck like this is a tough call on value.
The high value OBS trucks are F350, 4x4, solid axle, crew cab or extended cab longbed, and powerstroke 7.3. DRW VS SRW seems to be a wash.
I've been truck shopping for farm/tow rigs for a few months and the only good deals I see on OBS rigs are 460 trucks. 50/50 between manual and auto. The ZF5 itself isn't a bad trans, the flywheel and clutch suck IIRC and need swapped to an aftermarket unit.
This particular truck is an odd duck being TTB and shortbed with a manual 460. I don't recall seeing this combo before. I could see an OBS Ford fan wanting it for a daily driver or maybe even a 4x4 prerunner build. Someone obviously spent some time making the exterior paint look nice but the interior and engine bay tell the story that it's led a normal truck life and it's not a "BringATrailer auction $25k creampuff" rig.
$5k is a fair price, and in the right market it might bring $7k these days. It's not exactly what I'm looking for but I wouldn't pass it up at $3-4k.