Yup, all brass. Will try get some pics...
That's why I clicked. Not because I think you don't have them or anything. I just wanted to see some Casascius Coin pr0n.
I can't provide too much guidance on the 5 BTC Casascius coin as I have never owned one, but I did sell a brass 1/2 BTC Casascius coin not all that long ago for 0.76 BTC (but there was another coin involved as well so you can say 0.74 BTC as a more accurate price). That was my offer I couldn't refuse. I hope that helps guide you on what you may be able to get for these. Although with so many at once it might be a challenge if you're looking for a quick sale.
No.2, you'll need to find people who know nothing about physical crypto collectibles to get a number this high. Current market for Cas 0.5s is 0.6-0.65
BTC depending on condition. GLWS