The nine-year-old spent seven seasons with Henry Candy but his owners believe he may have more opportunities in Ireland than in Britain now.
A regular in races like the Stewards' Cup and Wokingham, Dinkum Diamond has been the victim of his own consistency and his mark only dropped below 100 for the first time in his career last September
"We've had him about two months, his owners are from the north and wanted him trained in Ireland this year," said Slattery.
"He's nine now and is having to race off 98 so it won't be easy, but if we can get him to the level Mr Candy had him then he'll be competitive.
"There are lots of valuable handicaps for him to run in over here.
"We've also got An Saighdiur in the same race and he's 10 now but will love the ground."
Evanna McCutcheon's old favourite Maarek also holds an entry in the Naas six-furlong handicap,