Sorry for your troubles, but the method described is reasonably what needs to be done. I can short-cut a few things to make it less involved, but it is pretty much as you are seeing it.
I've never had to drop the column from the instrument panel. A lot of work and a big pain to do. Also, while there has been known to be wear and/or damage to the electrical switch at the back of the lock (ignition switch - Victoria British part number 0-315), it is usually in good shape. It can be removed by loosening the 3 very small screws that hold it to the lock. If in good shape, you would not have to address any wiring, just the lock assembly (Victoria British part number 0-319; about $100). I'm not sure that includes the shear bolts (p/n 18-017), but they can be ordered separately. You can also try starting your car using a needle nose pliers to turn the switch shaft.
Next, have you tried spraying WD40 into the switch and then turning the key while 'rocking' the steering wheel? Also, not so obvious, remove the steering column covers and then ignition switch ( the electric piece on the back of the lock opposite the the key described above) and try using a screwdriver or other tool to move the lock from the back side to loosen it while again rocking the steering wheel and key. Douse it all well with Liquid Wrench or WD40 beforehand. Requires 2 sets of hands and sometimes works, it is usually what everyone has already done first, but just a thought.
Now, assuming the thing is really stuck good. The ignition switch assembly is held in place with 2 break-off bolts. The heads break off on tightenting to prevent theft and tampering. Bad news is they cannot easily be removed. Good news is they cannot be overtightened, so are usually fairly easy to extract once drilled or slotted, if you use those methods.
From there you a few choices, all involving the use of a cut-off wheel and either a drill, Dremel tool or an electric or air powerd cutter (all available cheap from Harbor Freight, if you don't have one). Making sure all other wires and apparatus (i.e.: signal lamp and wiper controls) are either clear, covered or removed from the steering column, see how easy it is to access the tops of the bolts. See if you can center punch the top of each bolt to give a place for a drill bit to find and start. With the drill or a bit in the Dremel tool, try to drill a hole in the top of each of the break-off bolts for an an extractor tool to remove them. The extractors are also available from Harbor Freight or Sears if you don't have them. Not as easy as it sounds. Besides the lack of clearance in the interior to do this without damaging something (why they go with dropping the column), the bolts are designed to be tamper-proof, so getting the punch centered and then gaining any kind of traction accurately with the drill is difficult.
Some have also tried to use the Dremel (preferred because it is smaller) to cut across the bracket into the tops of the shear bolts to create slots so as to be able to use a flat tipped screwdriver to remove the bolts (hence the remark about not being over-tightened). Again, accuracy is not as easy as it sounds and after 30 some odd years, the bolts could then be frozen in place to the lock and unable to be moved with just the screwdriver.
My preferred method is to use either the Dremel or an air powered cut-off wheel to attack the upper bracket that hold the switch to the column or go in from the sides to cut the the bolts themselves. Either way, it destroys the lock and brackets, but they're useless anyway. Faster with less of a chance to do other damage, this can be done fairly easily, though I advise caution and taking your time as to not risk cutting anything else or damaging the column in either cutting, chiseling or prying away the brackets.
The lock has a pin that goes into the column to hold the shaft from moving when locked. It generally just drops out, but from years of use, can be slotted and caught on the column or covers, so be careful in handling not to damage the sheetmetal column covers maneuvering it out. Installation is fairly straight forward; with the lock going back in 'unlocked' (column lock pin retracted). Just check the alignment before breaking-off the bolt heads or you will starting over again.
I hope that helps you. Let me know how you do or if you find anything else.
Safety Fast!
Art Isaacs