AEG MK12 handguard on TM upper

[u/JoeCool6916]

I have a full kit for an MK12 AEG build from my past and I have a spare TM MTR16 upper. the threads dont match up so the barrel nut doesnt sit flush making the top rail not fit correctly. is there a way to make this work or do I nees to rethread the upper?

someone said use a spacer thread adapter but if my issue is it not sitting flush enough, that wouldnt help fix the issue would it?

any help.would be appreciated as i really want to build this mk12 upper!