I can't help with the dimensions, but I can give you some tips on fly bridge removal. When I bought my boat the fly bridge had to come off before it could be shipped. The absolute smartest thing I did was contact the yard where the boat would be reassembled (Portland, OR) and make arrangements with them to fly their technician to Detroit to supervise the tear down.
He marked every wire on both sides of a cut and was careful about the process because he was going to have to put it back together. I paid for his airfare, a week in a hotel and rental car and meals. It definitely was worth it.
The selling broker was going to use a pry bar to lift up the fiberglass bridge so they could get the forks from a forklift under it. BAD IDEA.
The technician made them use long lifting straps to lift it and he was there to make sure they did it right and that he hadn't missed any wires between the boat and the fly bridge.
Here are a few shots of the process. Good luck and if you have any specific questions please feel free to ask.
It took several adjustments to the straps to get the bridge to lift level, not canted front to rear or side to side.
Checking before the lift to see if any wires still needed to be cut.
At this point my heart was beating about a bazillion beats per second.
The fly bridge is 12'wide x 24' long. They built a cradle for it and it had to come on a separate truck/trailer with separate oversize load permits. This cradle had to be enlarged because they had underestimated ( or measured wrong) the size of the bridge.
Here's Beachcomber topless.
They started the removal process around 0800. They finally set the bridge on the cradle about 1330, so it was a very long and nerve wracking process. In the end it definitely was worth the time they took because there were no problems during the reassembly.