'86 360 GLE B200E suspension and dipstick queries

[pettaw]

Had never looked before, and noticed that the dipstick tube on my car was just tied on with a cable tie :( Had this car for 9 months now.

Would this explain that I seem to be putting about a litre more oil in to fill it after an oil change than I expected to. (About 5.25 litres, according to my books it should be 4.5 litres including the filter)
Where should it screw in. There are two holes into which it could be. The one on the left or the right? I just dunno. HELP please.

I'm also struggling to find the cause of vague steering. It all feels pretty tight at town speeds, but get to 45-50 and the steering goes light and ponderous.

It failed its MOT last Jan due to among other things play in a steering arm, so I changed the rack for a recon one, which came with new track rod end balljoints on it.

Any thoughts on the cause of this steering vagueness? I had the wheel alignment checked and adjusted, all in spec apart from a slight difference in castor adjustment, which would account for the slight pull to the left. I tried to correct this by renewing the rubber bushes on the control arms. No difference. Any thoughts on this?

Lots of questions and a long post. I'm thinking top suspension mounts, bushes or main balljoints.

Thanks in advance

Andy