There are three objectives: Zeiss Imm 1/12", NA=1.3; Zeiss "DD". DD=0.16; Leitz "2"
Zeiss Imm lens serial number
The condenser is the Abbe type. It is centerable via a R&P
The two Huygenian eyepieces are labeled "2" and "4". "2" is 5cm, with the aperture 1.5cm from the bottom lens. "4" is 3.5cm/1.2cm.
R&P adjustment of condenser focus.
The condenser iris is adjusted by a short lever (arrow). Thumbscrew "A" adjusts condenser centering. "B" adjusts condenser focus.