Hi Jenafur ! ((Waving Wildly!!))
I like talent ignighter as a first step for folks who are still in 'gifted denial' - but like most IQ tests, it doesn't help with grade placement.
I would see if the program will allow you to give 'end of year' tests, or look at the 'scope and sequence' so you can see if he would have anything new to learn at the various levels of each subject.
If they won't, I'd look at some online Math Assesments, such as
http://www.singaporemath.com/Placement_Test_s/86.htmLanguage Arts is harder because Spelling could be at one level, handwriting at another, and Reading at a third level. But you can at least get an idea of what Reading level by using Lexile or whatever system your program uses to Google the title of some books your child is reading with the name of the reading rank system and see what level books your child is at.
For handwriting I like 'Handwriting without Tears' and you can see samples of their various levels at their website. I find their style of lined paper almost magical. If handwriting needs extra attention, I like their 'Print Tool' to analyze and teach a GT child what are the elements that make handwriting look pretty.
Enjoy!
Grinity