I
suspect one is larger in diameter than the other, which limits it to 4
possibilities. This may sound silly, but put it together and if it works the
same, great. If not, take it back apart and try again. You'll get it quickly
and feel smarter for having worked it out.

This is what I have done in the past. My guess is that this is probably a 4
element eyepiece with 2 sets of 2 cemented elements, similar to a Plossl.

It is my limited experience that in such eyepieces the similar faces face each
other so that also reduces the choices by a factor of two.

jon