Nah, give up given you're missing the lockring which is recommended to have.
The XT headsets are quite low stack (and decent).
M735 headset total stack is 32.7, minus lockring is no idea 30-31mm
Lower stack is 11.5mm so doubt you can save 5mm finding a different bottom half.
You could look to finding a different top part and a short locknut but that usually reduces threads.
Anyway you have some info there... 25mm threaded headsets...?
New forks would be easier and not a compromise.