Jim,
Hate to say this vaguely myself, but "it depends."
Here are two web sites you may get more specific answers from:
http://www.460ford.com/forum/
and
http://www.429-460.com/forum.htm
The engine may be worth more to a restorer if it is completely original and unmolested and includes all the original external parts and accessories. If it has been updated or overhauled in a non-original way it'll be worth less.
A good SCJ block by itself will be worth more than a vanilla 460 block if it is a 4-bolt main, thick web block. The only sure way to determine that is to pull the pan and look. If it is verified, and the block sonic checks OK for boring it may be worth upwards of $400; I've seen some for sale as high as $800. For comparison an A460 aftermarket block will be around $2000 new, but can be bored significantly larger, usually.
Best I can do,
Tom