Best bet for fixing it without welding, would be to stop by any machine shop and ask to buy a 3" or 4" square of sheet metal. Take home, drill hole in center to correct size, and a hole in each corner, Feed clutch cable through center hole, drill 4 holes in corner through fire wall, and drop in bolts.
Shouldn't cost more than $5 - $10 in parts, and an hour or so of work.
I have never done this on a car, but have done something similar at work before, should work great.