[ROVERNET - UK] Urethane vs Metalastic bushes

[Alan Gale]

Am about to re-bush the rear end of the 3500S.
Are the original metalastic bushes still available in reasonable condition?
If not, has anyone got reassuring words about urethane?
Scott's here in Melb can supply me with a softer urethane, but I have 
not been
able to source an alternative, and am wondering if the doubts I am 
hearing are
well founded or overly nervous.  I suspect the latter, but would like to 
know.
Assistance would be appreciated.
Alan Gale