Here mine Chronofigher Mark II Overlord.
I bought it some months ago, with broken chrono function and without the trigger. I'm opened it and made a very good clean with lubrication, contacted with eBay a UK watch-repairer who sell some genuine Graham spare parts and asked about if he had almost one original trigger. With surprise he found a little box with some different genuine Graham triggers and decided to sell them.
When they arrived I had tried all the triggers and found the unique perfect for it, but with a very little modify for to adapt it. Trigger is genuine, watch no.
Now works perfectly!
Last good news is that I bought, from another UK watch-repairer, the genuine box complete with all the sheets.
When I'll have time to spend, I'll try to restore the chronological function. Time function works perfectly, keeps time in an exceptional way. I own a radio-controlled watch for to check it. After months no one second lost! Every time I wear it, a lot of persons ask me about it. It doesn't pass unobsverved.
REALLY HAPPY TO BOUGHT IT!