Brushes needs to have the right hardness in order not wear too fast or score the contact rings. In the DVA magneto there is 3 brushes, one behind the points block. You could have a fourth one in the bakelite lid cover if the mag was equipped with that, for the killswitch. Hardness comparement should always be done with new bought replacements or homemade ones as well. Manufactures have numbers of the hardness but a rough comparement could be checked by scribing a line with the brush on a hard white paper and compare the colour and width of the line with the replacement. In doubt, rather use softer than harder brushes. It is always easier to replace the brushes than replace the contact rings. Retaining springs is important as well, local overheating can make the thin wire gauge springs soft. It is hard to mention some numbers, I have most measurements but not brush sizes or spring ratings. Pictures from the article:

Restoring a Rotating Armature Magneto [Re: Magnetoman]

John Healy Online content

BritBike Forum member

Years ago BMZ Bayerische Magnetzünder GbR had all replacements for the DVR but I don't know now.

And a picture of the regulator function from another article.

Continuing with information in case anyone needs it in the future ...

"Can someone suggest the best flywheel and cam position to impose the maximum rotational pressure on the timing gears to help hold them from falling out when removing the cover?

I'm answering my own question here because I think replies to my other questions in my post did not address this.

Vahan Dinihanian suggested recently to place the rear piston at TDC when removing the cover. I did that and found all the gears nicely snug.

Another suggestion for help from someone:

After removing the oil pump, screw in long threaded screws in the oil pump screw holes in the cover (best: custom made with T handles) until they gently reach and apply pressure to the cam gear inside. Then turn more slowly & gently and this will aid in pushing off the cover while holding the cam gear in place. I haven't tries this but maybe next time.

When mounting and line up the magneto gear, be aware that the mag gear could have been replaced, or the DVAR magneto could have been replaced and it is not at all certain that the round key is drilled at the same place, it can differ one or several cogs! It looks like the key is drilled by hand from the factory!

So I show in the picture the position the breaker should be in when pinion, cam gears and idler gear markings is lined up correctly (don't rely on the magneto gear marking!) 

Mag gear is mounted with the round key on the shaft because there is no use to reposition the gear differently on the shaft. Turn the magneto gear until the breaker is in the shown position and click in the last idler gear in position, then check if the mag marking is correct.

Mount and lock the breaker ring in max advance position and check the ignition timing preferably with a indicator clock, right on the piston top on both front and rear piston, a difference in timing indicate a worn timing ring on the DVAR. Replace the ring or divide the discrepancy between cylinders. If the mag gear marking does not line up, grind off the old and grind in a new marking for the future.

Breaker rings for the Indian is often marked with a stamped "I" under the outer band clamp, but unmarked or with other markings can have 45, 50, 90, 170, 180 degree division, or might be for a single cylinder bike.

Original grinding of the breaker lift ramp is elaborately done in 2 steps and can be reground but only by an expert with exactly the right size stone to get the right cam ramp for lift speed, I have seen repro rings that will destroy the breaker in short order.

Usually the adjusting range between min. and max. on the ring is too large, so when max advance timing is set at the stop, the max retard is way after top dead center, it should be at, or max a couple of degrees after tdc. This can be fixed in different ways, make a stop for, or lenghten the adjusting arm, or restrict the slot length on the backside of the breaker ring, or put a stop clamp on the free portion of the handlebar wire. Running the motor with ign. after tdc is not good.

Don't be tempted to run max advance timing without a stop, attemting to hear or feel enough advance timing, because it is not always felt or heard that the motor has a too advance ignition. I fried an engine like that with too advance timing.

If you want to experiment, adjust the max advance stop in small increments and check ignition plug colour (can be difficult to see colour differences with the new kind of fuel in the pumps), cylinder temp or other tests instead of only rely on butt feel or sound.