Thanks for all the advice on the bush replacement. I took a deep breath and started on this today, about 2 hours later it was all complete. Inserting the new poly bush proved to be no trouble at all...it just slipped in...after a 10 minute boil! Only difficult bits were the withdrawal of the steering column and its later extension with the recess in the correct place to accept the universal joint bolt. Not a one man job though - needed to call on the assistance of Mrs D who was happy to get her hands dirty in a common cause and is therefore awarded a gold star.
James