His wife died of motor neurone disease 17 months ago and he has been training daily as well as shearing, to help promote awareness of the disorder.
While shearing mainly in his home area he has done two seasons at Quindanning in Western Australia, and six in New Zealand, working for shearing gangs in Taumarunui, Balclutha, Winton and Hastings, where shearers he worked with include champion Hawke's Bay gun Rowland Smith.
World Sheep Shearing Records Society secretary Hugh McCarroll, of Tauranga, has also just received an application for the second bid to be made on April 27 near Kojonup in southern West Australia by Louis Brown, originally from Gisborne but now based in Bunbury, south of Perth.
King Country farmer Ian Buchanan will judge Saturday's record attempt with Peter Artridge, of Mulengandra, NSW, Ralph Blue, of Yeoval, NSW, and Dave Brooker, of Lucindale, South Australia.
Terry, who had two-hour tallies of 114, 119, 118 and 115 when he set the record, will be present at both of the attempts over the next month, wishing the hopefuls all the best and helping run the attempt by Brown.
He was also present when now New Zealand-based Australian shearer Beau Guelfi made an unsuccessful bid for the record in June 2016, bowing-out at the lunch break with the record already well out of reach.
Sheep will need to average at least 3.4kg of wool each and Clayton will need to average more than 58.25 an hour and clip more close to 1.6 tonnes of wool during the day.
No shearer has yet gone under a minute a sheep in an adult merinos record bid, New Zealand shearer Stacey Te Huia having come closest when he averaged almost 58.9 of the finewooled ovines an hour when he set a nine-hour record of 530 four years ago in New South Wales.
There were no record attempts in New Zealand during the summer, McCarroll estimating it was at least 20 years since the last time a summer passed in New Zealand without a single bid.
The society manages world record shearing bids for the standard eight and nine-hour working days, and currently has records on its book from solo records to eight-stand tallies.