Fuel tap. Getting it pointing the right way.

[Barnsey]

Whoops!  I didn't think of annealing them.  .... But should I need to if they are brand new? 

I've heard stories of modern day MOT centres who expect all seals to be modern synthetic rubbers, for instance vintage filler caps which are brass on brass. 

[V500]

Yes you should as the stamping process itself cause work -hardening, plus they may have been sitting around for a while.
I must admit I wouldn't use copper washers for fuel taps, but if it's worked for you then fair enough.