Captain, I had the Gamescience miniatures separately when the Battle Manual came out, later in the Battle Manual boxed set and during my more active Star Fleet Battles days...
The plastic ships were put under the Starline 2200 line. They are completely indistinguishable from my original Gamescience ships... it was my understanding that Task Force Games had also liscenced the Gamescience miniatures since ADB had also liscenced the ships from the Tech Manual for SFB. The original Klingon D7 was white metal, quite soft and that miniature never stood the test of time well. The original Romulan and Tholian miniatures was very small, also white metal.
Fast forward to today... while I have no idea what Zocchi/Gamescience is doing these days in regards with the D7, Romulan or Tholian, they are supposedly supplying the plastic Federation ships for Federation Fleet Box #2. ADB has stated a number of times that these ARE the plastic ships, not new molds. I haven't bought this fleet box to confirm the contents, but I have handled it and it is quite light in comparsion to Fleet Box #1 with it's metal ships.
At one time, there was a metal casting of the Federation Heavy Cruiser. A direct comparison of the one I have shows that this mini is a totally new casting and doesn't have any resemblance to the plastic version in a number of areas. The plastic one is still superior in appearance!