Help with Read/Write automation, re-recording automation)

So, I arm the track (an audio loop) to record. Write Enable is on.
I set a reverb send on this channel to the required amount, press record, click the send button to record the automation, and then spacebar to stop.
Write enable off, change the send to another amount, press play, I see the send correctly jump to the required amount.
I repeat this process a few bars in but I turn the send down as I want the reverb to be less at this point.
Press play, the send jumps to the 2 settings which I just recorded.
So far so good.
Now, I want to change my first setting as it's not the right amount when I have other instruments in the track.
I record a new setting "over" (at the same point in time) the old setting.
Now both settings are active.
How can I see this (it's not in the event editor) in a graphic form?
There's nothing to select in the automation lane (which would seem to be the obvious place to look)
How can I change this?
It should be a simple task, but it's another thing that I find is overly complicated and not well enough documented.
Please don't tell me it's another bug!
Thanks in advance people!