During reassembly of one of the smaller bikes I use the swingarm bolt to help with assembly of the front forks. Essentially it's a long 10mm bolt with the same 1.25 threads as the smaller bolts that go into the top of the forks. I suppose it would be easier to use if it had a handle welded to it like the tool in the parts manual but I've never had a problem pulling the fork uppers up into the covers or through the triple tress. Once in place, carefully remove the long bolt, and install the correct fork bolts. Sometimes the upper fork may retract a little and get out of reach of the fork bolts, but if you're careful and don't move it too much, you'll be OK.
Over time I've collected old m8, m10, and m12 long bolts to use for various purposes such as this.