In 1843 an account of one of his procedures was reported in the Maitland Mercury:
RESTORING A NOSE - This operation has lately been performed by Mr. Liddell, surgeon, of this town on a assigned servant ofRichard Jones, Esq., Bolwarra. It is usually performed, as in the present instance, where accident or disease has destroyed a part of the nose, by dissecting a suitable portion of skin from the forehead of the patient leaving only a slender attachment, whereby its vitality is for a time maintained; this skin is then adapted to the edges of the deficiency, previously pared, in order to reduce them to the condition of a recent wound. When the operation is successful, union of the parts takes place in three or four days. By this operation, which is termed by surgeons the rinoplastic art, deficiencies of other parts of the body, as the lip, ear, etc have at times been usefully restored.
Margaret Liddell, wife of Andrew died in 1871 and Andrew Liddell died aged 71 in 1877 -
The Late Dr. Andrew Liddell - It will be seen by a notice elsewhere that an old and highly respected Maitland resident, Dr. Liddell, has died in Sydney, having attained the age of seventy-one years. In his more vigorous days, the departed gentleman was an active sharer in all local public movements, and brought to their consideration much shrewdness and earnestness. He was very successful in his practice as a medical man, and when he left Maitland after the death of his wife - whose exertions contributed largely to his worldly advancement - he was in very comfortable circumstances. Dr. Liddell sat for some time in the West Maitland Municipal council, in its early days, and three times he unsuccessfully contested an election for the representation of West Maitland in Parliament. Since the death of Mrs. Liddell, the doctor has become gradually more feeble in health and on the occasion of his last visit to Maitland, during this year, was very much aged and worn. He has lived for some years in Sydney, and died there on Saturday morning, after a severe illness of only about a day. He leaves two sons and a daughter. The remains of the doctor will be buried this morning.
Notes and Links
1). Note** A Dr. Liddell with wife and child arrived in South Australia on the Glenswilly in 1839 with the intention of travelling on to Sydney. (possibly William?)
2). Fanny, daughter of Andrew and Margaret, died age 11 weeks in December 1852 
3). Helen Elizabeth, eldest daughter of Andrew died on 12 May 1859 age 17 
 Ancestry.com. New South Wales, Australia, Unassisted Immigrant Passenger Lists, 1826-1922 Original data: New South Wales Government. Inward passenger lists. Series 13278, Reels 399-560, 2001-2122, 2751. State Records Authority of New South Wales.