Yes. They're "pewter", really a mixture of tin/zinc or maybe tin/lead. Glued them together with CA- typically about 4 to 6 pieces each one. They were released by FASA as kits (to go with FASA's ST game) and, some years later, by Rawcliffe Pewter as assembled, unfinished collectibles with pewter stands instead of the transparent plastic.
Amazing to see a FASA movie Enterprise that doesn't have the pylons going every which way (they were in scale, but that lead was a bit TOO flexible for my tastes) or a KBOP without the guns busted off. I've got a couple of those still in my stash. My favorite is the Andor class heavy cruiser with its protected warp nacelles. Locknar was also nice (I made a refit by adding refit engines from a trashed Enterprise). The only two I wish I had which I know were issued but weren't out very long were the Ramora class escort and the Northhampton class (weird nacelle configuration). Some of the Federation designs (of those not made into minis) were hit and miss. But some of the Klingon designs were VERY cool looking IMHO. The mini designs provide some nice ideas for kitbashes in larger scales.
That brought back a memory--I bought a couple many years ago--unpainted and I knew where they were. So I dig them out and the TOS Enterprise engines have wraped below the secondary hull on the same side--looks like a transporter accident!