These are Amarillo Design Bureau Starline 2500 series ‘Klingon E4 Light Frigates‘ cast in metal several years ago. At 36 mm in length, they are much larger than my old escorts. They will be used for a class intermediate in size between my F5s and D7s. The E4s and F5s will thus be reversed by size, but that avoids re-labeling all the old models.
Decals on new ships are from Mark’s Models and Toys.