I wouldn't touch one. They are notorious for being rust buckets, to the point they are not economically viable to keep on the road.
I've yet to see a rust free SLC, you may find the odd concours low miler one but certainly not at that price.
In terms of affordable classics don't buy a SLC. The SL of that era didn't suffer that many rust probs, may be a better bet but will cost you significantly more.