Rich, I'm far from one to give you advice, especially sitting where i am, not being in your shoes, with your responsibilities. But from what i know about you, you have a skill set that very few people have. From the sounds of it, you are basically carrying your current employer, who I'm sure knows it. I'm sure if it happens to go south on your own, you could always secure another job, either with your current employer, or one of his competitors. Here's how i see changing jobs, which I'm sure you know in construction is a very common occurrence.
I do the same level, speed, quality, and effort at work, no matter who i work for (myself included). Because of this, and I'm certain my charming personality and dashing good looks
, i tend to work for contractors over an extracted period of time, often longer than the original call out. If work is very slow, I'll happily plug away. However, if things sour, i start planning my escape plan. The most important part of it is how busy everything is. If there's no work anywhere, I'm lucky to be employed, so nothing is done. But, like a catfish roaming to a new feeding pond, you have to move when the water is high. The economy seems to be stable and growing (in certain areas), so if the water's high enough, it might be time. Only you can make that call, but that's how i look at it. I'm sure you will have growing pains from time to time, but the lack of drama and working to standards that you alone set I'm sure will be very rewarding and profitable.
good luck man!