Weigh it and find out what local scrap iron price's are. That would be a good baseline IMO. I wouldn't think it would be worth much more than core value.
I have 1/2 dozen good used FH camshafts that could be reground but the cost of shipping to the cam grinder makes it financially inefficient.
I've got 50+ Flathead cam cores... Some cam grinders will pay $30-40 per core plus shipping. H&H flatheads buys em, too.