My Standard GFL arrived with two Zeiss 10x18 eyepieces, of a high eyepoint.
However, they were undergoing delamination. Besides, their top end is a strangely oval, hard plastic shape. I wonder why has Zeiss made such an inconvenient eyepiece. They press against the eyes of the beholder or into his spectacles!
Not sure what you mean with oval shape. So a kind of protectors on top of the eyepieces? You could remove?
Delamination is a common problem with those eyepieces. If it is starting just at the edge of the ocular you might just put a drop of immersion oil into and it will fill the gap. Otherwise Caedex balsam will do better to repair.
So instead of the originals, I am using a pair of Olympus 10x/20 L eyepieces. They provide a wider FOV, which is very pleasing
I also checked these Olympus 10x/20L eyepieses. They are nice. But they cause a slight incorrect chromatic error at the outer diameter of the FOV so finally replaced by the KPL's.
(relative to the smallness of the microscope at least). For the phototube I use the Zeiss 8X KPL eyepiece.
I also use such
I still lack a proper pair of flexible rubber eyepiece tops - the inexpensive Chinese covers available on eBay are a poor stuff.
What is the reason why you want to use those rubbery tops?