Thanks for the reply. Well, I overstayed more than 6 months and was told I faced imprisonment. Well that's not what happened. I rode straight to the border to try my luck. Nobody knew what they were doing, the boss came out and frowned at me. There was talking and phoning and a hell of a lot of nobody knowing what to do with me. Then, out of the blue, I was free to go. Not even so much as a 1000b overstay fine. Just thanks very much, sorry to keep you, glad we could help. I still wasn't quite sure what was going on and didn't stop till I was well clear of customs. I followed some advice and kept my fool mouth shut and it worked. I got a business visa this time, it's a multi entry so no more messing about getting in and out of Cambodia. No customs this side so i can leave the bike here as long as I like, theoretically.
Unlike everything else in Thailand, that was blissfully easily. All I had to pay was a 20b processing fee.
Shattered now and crashing at the Dugout. No police along the way, no dodgy fees or fines (so far). Got caught in a little rain, nothing bad and once I crossed the weather was spectacular.
I am a happy Jack.
This is a lesson learned. I've been phoning and visiting the customs people and always got different answers. I will never trust these people again, i'll do my own research from now on. This ended very well but so easily could have ended with me in prison and my bike in a little cube.