There is NO approval necessary for long guns, and there are no "lists" of said guns. As long as it complies with the AWB (no evil features), any long gun is "good to go".
I bought one of these from Four Seasons back in 2002 (and sold it in 2006).
Is it okay with an FID, since they only sell it with 10-round mags?
I ask because it seems somewhat similar to the Ruger 10/22 in its magazine capacity. There are plenty of after-market high-cap mags, but Kel-tec doesn't sell them to my knowledge.