Is it a monumental job to remove the lower steel part of the dash in a 60 model?
No, it's not too bad. If you've already got the dash top off and you're going to all the effort and expense of a re-trim then it's definately worth doing. Just keep undoing bolts and screws until it all comes out. You'll need to drop the steering column out of the way or even better, remove it all together.
I did this job on my '59 a couple of years ago and it wasn't a monumental job, just a bit time consuming. Don't expect to drive it around the trimmers shop while it's apart though!
Dave