Punka
The wing gear as speed brake on B747 Classic series was disabled decades ago. I used it a few times - as noisy as hell. In the event one wing gear fails to extend we used to land on the three remaining. Crazy wing low attitude on taxi off the runway and anyway there's no (legal) way to retract a wing gear by itself.
The throttle bar was vital when flying with those ghastly JT9D-3A engines. Above FL290 it was slid into place to prevent taking off too much thrust which would lead to the self destruction of the engine usually. We descended at M.86/340 kts as I recall it. Those -3A engines were a nightmare to handle especially on the ground. We were so glad when they were modded to -7 status and actually worked.