Did you know, the bristles of a fly are groved?
I tryed the L.W.D. Lens Carl zeiss Jena planapochromat 16x/0.20 without realy looking for my setup. The tubelength wath reduced to 130 mm and no tubelens insttalled. Instead the B&L ocular 10x was still sitting in there.
The working distance was almoust 15 mm.
Edit: exchanged foto for a manualy cleaned one