When do you do the bolts up on a maon's mitre?

This weekend (tool hire place dependent) I will be having a crack at my worktops with a 1/2" router and jig. I've used my 1/4" router for a couple of bits and bobs, but never done a mason's mitre or cut worktops before.

When do I bolt the two halves together? The reason I ask is that I have an L-shaped kitchen, and once the worktops are on the carcasses there will be no access for a spanner.

So, do I:

1) Cut a big hole in the side of one carcass to stick my arm and a spanner through (I have some spare material to patch it up, and it won't show anyway)

or:

2) bolt the worktops together when pulled away from one wall by about a foot (thus still fairly well-supported), and then slide them into the corner?

Obviously the second is preferable if possible, but is it ok to bolt the worktops into an L-shape and then slide them into the corner, or am I likely to knacker them?

I wouldn't worry too much about breaking the joint as long as both pieces are fairly well supported, those bolts make very strong joints. I have moved worktops like this.
How come you have no access when the tops are in place?

Well, there is a soil-stack in the corner of the L, with appropriate boxing around it (a 12"x12" square taken out of the corner of the room)

So, the corner couldn't be filled with a corner unit (without significant modification, anyway).

The units that fit into the corner: on one side you have an 800mm unit with a 600mm door, 200mm of the unit are overlapped by the first cabinet on the other run. This means that you have about 40cm between the end of the 800mm cabinet and the wall, and a gap of 60cm (i.e. a cabinet depth) between the second run and the other wall.

This, combined with the location of the sink (which has dictated the direction the mitre must be cut) means that the bolts will be inaccessible.

Now, I've fitted hefty batons to support the units in that corner. Because the worktop is screwed onto the units from underneath, there is little chance of that corner lifting. When it is all done, cut-outs and all, I will use adhesive to glue the worktop onto the batton, to prevent it lifting no matter what!