Just courious, how many motors have you had built?
New motor with a lot of machine work or a simple rebuild?
It's rare a engine builder gets a motor back to you in a hurry. I've had one sit for more than 6 months and yea, I was pissed, but I would never call the guy a crook. He built me one hell of a tough motor. It was a brand new build and they always take a lot longer to do. My bill was also a lot more than I was told. I wasn't real happy about that, but all the extra cost was from upgrade of parts. (ie: 1 thing was a new intake almost an extra $800). I could have been pissed about that, but I felt it was worth it in the long run to have the best parts available for my investment.
The last thing I want my builder to do is get in a hurry to get me my motor back because I'm bugging the crap out of him.
I'm not saying it's right for a builder to tell you it will be 6 weeks and its 12 weeks and he hasn't been in contact with the customer. It happens and I also would not call him a crook or scammer just because it took to long.
IMO I need more info and to hear his side of the story before I can make a decision.