(a) You previously said that the eyepiece was
30mm, so 30.5 should not fit.
...
but your photo shows it to be nominally
31mm so presumably the adapter
would fit [rather loosely]
(b) The primary image is the one that the objective forms [*]
... So if you use this adapter [
which, if I understand correctly, replaces the eyepiece with an empty tube] that’s what you will be photographing
Your instrument will therefore no longer be a compound microscope ... but effectively just an objective on the end of a tube.
This may, or may not, work for you ... I cannot judge.
MichaelG.
.
Edit: [*] for an infinity corrected system, read that as ‘the combination of objective and tube-lens forms’