Cedric, let me have a look in my garage. When I did my Patrol's master cylinder in Namibia I am prety sure I had those two rubbers in the kit and I did not use them.
In the meantime, maybe just pull your reservoir out and see what the problem is? Maybe its just not sitting in its right place or something.
Last option is just to go to the spares shop and let the guy bring out a couple of Hilux of Cruiser kits, I am sure these rubbers you are looking for are all very similar and you will find one that fits quite easy