The top rubber from a car shock absorber should do the job
Yep, I'd suspect that's just what Rover has used.
Should be easy enough to find something in this listing
http://www.eziautoparts.com.au/steering-and-suspension/suspension-bushes.htmlYour local Repco, Bursons etc. will be able to get them by the Mackay Rubber part number given. Or just take the old one in as a sample.