OK, just to close this out for anyone in the future who needs help....since finding information on Nighthawks is about near impossible due to the start of their production and the untimely closing of Meadowlark.
My Nighthawks came from Craigslist. They were purchased for $200, and functioned 95%. Nearly every driver dust cover was pushed in (besides the tweeters). There was some tuff stuff expanding foam glued onto one of them, and the other was a very expensive cat bed in the bass port. I must have vacuumed out 5 lbs of furr....lol. Because of how cats are, they rub on everything and claw stuff...both speakers needed some love. Both were overall very dirty too.
I'm currently in the process of restoring these beauties. The quality of the materials is exceptional, so the restoration is actually going really well. Amazing the transformation that is possible when using good materials. Its laborious, and I suspect it'll take me another couple weeks to finish the cabinets.
Tracking down the replacement drivers took a little doing. Meadowlark put self adhesive vibration damping material on all the drivers, and that covered the labels on the driver's themselves. Remove the damping material, and the labels come with it...and are not readable...so hopefully this info below helps someone in the future.
Now, for woofers and midranges, here's what you need:
Replacement: Scanspeak18W/8434G-00 (direct drop in replacement)
Original: Vifa M10MD39-08 (but with a slightly different cone)
Replacement: Scanspeak10F/8424G (frame is about 5mm smaller diameter, so you can notch the mounting holes, or modify the cabinet...or maybe make a mounting ring.
If anyone would like to see the progress or finished project, jsut let me know and I'll share. Again, hopefully this helps someone down the road.