Took a picture of my Rovers today, my phone is getting worse...

[Linked Image]
[Linked Image]

I am guessing 1957, 1958, 1959 {??} Might be wrong, but I recon maybe 1957 they changed to the blue base (from the yellow Wizard), 58 they added height adjustment (see picture below) and in 1959 they went to the green big 'V' base. 1962 they changed again and around that time changed again to the blue base with the diamond badge. Around 1965-1967 they then changed to the blye base with the common white and red Rover badge, then around 1983-4 they became red with a black plastic Rover badge.
Jack might be able to offer more info.

[Linked Image]
As you can see this one is like my base above but without height adjustment.

Cheers everyone!

Thanks for reading!