Just picked it up yesterday. Waiting on manuals I ordered. This is the fourth hoe I've owned in 20 years so I'm pretty familiar. This is the manual shift with the shifter on the floor. What is the button on the gearshift for? Release clutch? When do you use it? To shift while moving?
Prolly to put it in neutral when loading trucks. Many times you get to the truck before the FEL hoist is high enough to clear the side of it.
You should have a button on both the loader lever and the manual gear shift lever. They both do the same thing which is place the transmission in neutral. The one on the loader lever is used for loading trucks so you don't have to shift into neutral with the FNR so you can keep your engine rpm's up for faster loader cycle times, and the one on the gear shifter is used when shifting gears on the fly.
Good looking backhoe you have there. The rollback looks loaded. I don't see air between the tires and the bed.
I think not an overload. The truck is a tandem at least 15000 per axle. I'd guess that tractor at 16000. I wondered about height under wires & bridges. I think he's OK there too.