1997 Other Rover Models Question about PG1 (Diesel) gearbox

I just got a replacement gearbox for my Rover from the scrap yard. I am not sure if it’s any good or not.
If you put a pair of mole grips on the selector shaft you can find all the gears but when one is engaged if you turn the centre shaft that plugs into the clutch it does spin the drive shaft but you can hold the drive shaft just with your hand and still spin the centre shaft with no resistance. Almost like it’s in neutral.
When I got it, the end of one of the drive shafts was practically welded into the bearing and was hard to get out, the drives shaft actually had marks on it that look like weld.
Now the box does not have any oil in it, but should it do this or does it just need working a bit with oil in.