I have no idea what these are. They are unproduced vehicles. That's all I know. Looking at the mechanisms, they are likely from the '90's. But, what year and what they would have been is completely unknown to me.
I wouldn't go so far to say these are interesting or good. Really, had they been released, they look like incredibly terrible toys. But, they weren't released. So, I think collectors dodged a bullet in that regard. These are definitely examples of where just being unreleased or rare is not enough to make something super desirable. While both the unproduced Vortex and Cobra Eel looked like decent enough toys from the proposed 1995 line, these things are not up to their quality.
The colors, spinners, accessories and general blockiness of the designs look very dated now. It's amazing how toys from the 1980's oozed realism while still maintaining playability. The balance between those really hasn't been found since then. Even Hasbro has struggled with the Joe line. What few new vehicles they're released since 2005 still don't quite measure up to the vintage quality, realism and fun. The vehicles below are a prime example of that. These are poorly colored, poorly designed and generally rather boring. But, they are unreleased items. That's the most interesting thing about them.
If you have any info on these, please comment below.
Edit 6/14/2016 -
Thanks to scockery in the comments below, these are the original concepts for the Power Fighters vehicles. You can see them in the 1993 G.I. Joe catalog. Thank you very much!