Bob, Cobba, Gentles
Thanks for your tips, always related to the topic.
As far as my research got, I think prechamber is hold in by injector nozzle cap nut, with copper washers among there.
Let see some pics about (Still need shop manual);
1 - The injector body (pic from net, off course, mine is worst);
2 - The fuse holder and nut;
3 - The prechamber on place;
Now lets see: In this case fire holes are opposite fuse hole, therefore...the right pre chamber will be...
4 - this one... is it? As you can see there is a hole to the fuse in front of fire holes;
5 - Its the same prechamber, but it has another fuse hole behind fire holes (and missed the dowel to align fuse hole);
6 - Diferent view of prechamber.