Both objective lenses are bi-convex.
A: dia = 6mm, f = 5mm
B: dia = 9mm, f = 13mm
The objectives screw into the brass instrument body. The outside threads are for the Lieberkuhn reflector.
Lieberkuhn reflector is silvered on both surfaces. Diameter = 4.4cm. The diameter of the center hole = 7mm.
Assembled instrument.