Current update; many thanks guys especially Bill and Donald, those photos will help many people for sure. ''My'' trigger is different to the one in the photo, but that's only a minor variation.
I did check the piston and it seemed ok, and I did buy a new sear; measuring the overlap on the ''sawtooth'' on the rear sear, where the front sear actually sits; I found that the 'tuner' had removed some metal; the new one had a measurement of 1.1mm; the 'tuned one' was only 0.5mm; hence the gun went off even with the safety engaged!!
as well as randomly self discharging, or discharging when the barrel is closed. A new trigger adjusting screw and removal of the little coil spring from the trigger, produced a completely different trigger action, now one stage and much heavier and safer.
Now much happier, and I can now put an Omega trigger back together in a couple of minutes, so not all time wasted. Plus another gun back to what it was supposed to be. Also perhaps a warning, this was a ''tuned'' version; tuner unknown; but it was in fact a dangerous result and could have caused a serious accident, thankfully it hasn't.
Thanks again guys, lots of appreciation for the time and effort, and I'm sure many others will gain the benefits. ONE UP FOR BBS and ITS MEMBERS.
abellringer