In the OEM factories they don't break the seal before installing the lever, that's why on your first brake bleed you'll often see little white bits floating in the fluid.
Ah okay, so just assemble and tighten up, press the lever and all good 👍 haven't got spare olive and brass thing plus the tool to install and bleed kit etc and just want to be sure I can install without all that as I don't want my bike out of action while waiting for stuff if it doesn't work.
Ta for the advice, think I'll pop the seal and go for it. Wil update with the outcome.