So far I've had Manchovie upgrade one of my guns for me. I went down to ASC, he happened to be there, so I thought why not invest some time in improving the internals of the new AEG I just purchased.
Well the upgrade had some minor problems, initially I had wanted to re-use a supposedly compatible V2 mechbox. Had it from a previous AEG and it was already upgraded. Either way what was supposed to be a simple upgrade turned into an all-night affair. But Manchovie was good enough to let me watch the entire time (which is great as I now don't fear disassembling a gearbox) and although things screwed up was willing to spend the time necessary to get the gun working right. Eventually I went home a little later than anticipated but with my gun working and ready for action (still works great to this day).
I wouldn't consider myself a friend of Manchovie's, simply a customer, I found him to be a great gunsmith. Whatever happened with your transaction probably just boils down to lack of clear communication resulting in expectations that could not be guaranteed. Besides the only time he's ever going to want his handiwork to fail is when you're using it against him on the field
I hope no complaints like this one make him question his gunsmith service.