Welcome to The Firing Line!
Sorry I can't help with dating your IJ. I have a Target Sealed 8 and they are fun guns, but I don't get mine out much. If you open a new thread you might have a better chance at getting your question answered. Many will see the thread start date and not even open it. I looked only because I own one.
I wonder if this necro-thread sets some kind of record for once and done posters opening old threads?