Spencer Downey helped negotiate an "affiliation" agreement between the two clubs last summer. The pact saw 21-year-old left-back Dummett arrive in Paisley on loan last August while midfielder Newton, also 21, followed on another temporary switch in January this year.
Downey told Press Association Sport: "We're already looking at the next batch to send north. It will be hard to manage the expectations as Paul and Conor have done so well that people will think everyone we send up will be just as good but we are working on picking out the best young players for St Mirren to look at."
He added: "What St Mirren have achieved this week has been unbelievable and it's made the people at Newcastle sit up and take notice."
Both players played key roles in Saints' League Cup victory over Hearts last weekend.
Dummett set up Steven Thompson for the team's second goal, while Newton scored the crucial third to hand Danny Lennon his first trophy as St Mirren boss.
But the duo are out of contract with Newcastle at the end of the season and Downey believes they would have no problem signing on with the Clydesdale Bank Premier League outfit permanently.
"Conor has really taken the club to his heart and Paul is the same," he said. "In fact, Dummy told me the other day his dad is even talking about getting a St Mirren tattoo.
"The way the club have treated the two lads has been unbelievable. From the chairman Stewart Gilmour, to the chief executive Brian Caldwell and then both Danny Lennon and (first-team coach) Tommy Craig on the football side, they have all been great.
"If prizes were given out for being nice in football, St Mirren would be in the Champions League."