A good question. On the Sterling it gave the bass more balls. It was a while back but it transformed a nice bass into a great one.
I would say that the East pre, allowing a 3 EQ Stingray to take on the characteristics of the 2EQ, would be worth investigating as it would save you having to find another one. It sounds like a very good solution.
Now a Nordstarand and a 2EQ replicating pre might work wonders.