Looks like the EGR vac amp. You can remove it before you remove the EGR valve. Make sure to plug the supply line where it comes off the engine vacuum pump.
turbobenz is more able than I am (no mean feat to be more able than I am

) if he removed the transmission vac amp and has tolerable shifts. I futzed with the VCV and bowden cable for days and couldn't get acceptable low throttle shifts. I didn't try a transmission modulator off an MB model with no transmission vac amp. That might be the difference. gsxr thinks the valve body is programmed differently as well.
The attached vacuum diagrams might help.
Sixto
87 300D