Manhattan testers often offer a fee-based service: interpreting your child's IQ test results. Many concerned parents, often first-time parents, eagerly sign up. For example, if a child's IQ test scores are uneven, a nervous mom may want to understand how this could have happened.
Parents worry if their children have deficits. IQ tests like the Stanford Binet, OLSAT, and WPPSI offer the illusion that the test results can clearly define children's IQs, strengths, deficits, and future potential. In fact, four-year-olds are tempermental and subject to whim and fatigue. IQ tests measure much less than what they are supposed to, as evidenced by how coachable they are and how many children who bomb preschool IQ tests go on to very successful academic careers.
For these reasons, I think you should think very carefully about your objectives in going back to testers for IQ test feedback. If your child is performing well in nursery school and you have achieved your objectives for kindergarten admission, there is absolutely no reason to linger on the IQ test results. Your energy can much better be spent looking toward future goals.
If your child does have clear signs of social skills, fine motor skills, language skills, or other deficits, I would consult Toby Glick of ParentConfidante (646-300-1881 or toby(at)parentconfidante.com). Toby looks at the whole picture: how your child is performing in school, with friends, and with you in your home. She is sensible and cautious in the advice she gives, never prescribing unnecessary and unproductive remediation.
Finally, if your goal is for your child to improve his or her performance for future IQ tests, I would just get started with prep. A good place to start: Kindergarten ERB / WPPSI Test Prep Kit Performance Section: Best ERB Toys and Books