My crane never made it to the Mun as it was very difficult to both launch and land; even with much strutting it was a very wobbly spacecraft. I'm making a more successful attempt with the base parts on wheels connecting with docking ports strategy. I would recommend coming up with a consistent way of making your base parts so that they all have the same, well..., base. I'm using parts from the Kosmos space station mod with rover wheels attached and, with the help of the sub-assembly saver, I can use that same assembly (truss, wheels, docking port, 4-way) on all my base parts. I imagine something similar could be created with stock parts as well. To ensure the thing actually docks I did two things. One was to let the first part of the base free-wheel to the lowest local point with the hope that it will be a fairly flat place and second I placed 4 of the Place-Anywhere RCS thrusters around the docking port of the bit of the base that was going to "dock". Once I had manoeuvred the second part into place it was just a case of giving a few bursts of RCS for the ports to lock. I'm also trying to make sure my base parts have a similar mass so they will sit similarly on the rover wheels. Picture: