When I built my 6204 I found that the Brevet Crown should be a 6mm. I used the Brevet crown from Raffles Time and modified it as outlined here: https://rwg.cc/topic/140709-6mm-brevet-crown/?hl=%2B6mm%2B%2Bbrevet#entry1046879
The minute hand should be 13mm from center hole to tip. The early watches used the longer hand. I bought mine for the 6204 and 6542 from Helearou That puts the tip right at the chapter ring, which has a diameter of 26mm. The hour hand came from a long time looking for a pencil style in the right length and hole size. If memory serves, I got it from OttoFrei and had to squeeze the center hole a tad to fit. The second hand is stitched together.
:https://rwg.cc/topic/172220-look-ma-new-hands/
I used a 'Tiger' case, engraved with 'Brevet 6204' and serial number by JB, and ETA 2846 movement. The dial is a decal I made, pic attached welcome to use. . The bezel is one of those I had made for the 6542, modified and aged. The bracelet is unmarked, per gen.
I really love the way the 6204 looks, and is my 2nd favorite by a hair to my 6542.