If the only thing that isn't original on your bike is the ammeter, then a CZ27 would be a "must have".
Most people, including me, are a long way from this.
I have never owned a British bike where the ammeter tells me what I want to know; the needles just flick around too much. All mine let me know is if the dynamo is sending some power to the battery i.e. charging it or not.
I have a Triumph which had Rotor/Stator problems. All the ammeter told me was when the Stator had burnt out i.e. no charge to the battery.
I fitted a little Voltmeter to it, which tells me that the alternator is working and that the regulator is working when the bike gets a good thrashing.
If it bugs you, then hunt down a CZ27. If not, put on whatever looks the part.
Oh dear, not the 'removing history' argument again...
It's a good job nobody thought that when it came to rebuilding the engine, I doubt it would run very well with all those 'original' worn out parts...:laughing: .....
Or worse, that it was made into a metallic purple chopper in the 70's, that might cause problems blending in at a 40s event....
Fortunately, history isn't static or frozen at a given point in time....All the changes that are made to the bike are part of its 'history', even the ones you might make, like fitting the correct ammeter....Ian
:laughing: ...As 'Uncle Bunts Chop Shop' did turn my plunger A10 into a purple chopper back in the 70s I wonder if it's still out there in all its historical (hysterical) glory....KFH 151...are you there?....Ian