Can you sign the message "I'm madxista selling 10 chips from zefir's batch 8. Thu Jul 25 2013" from address 1HWcHT9ejkAeHnuwpzGj1uMenZfnUkXB9r to prove you own them?

That reverse auction used John as escrow; have you made an arrangement with him?  I don't really want to bug him over such a small amount, but I guess the fee itself would be alright.  I think my forum reputation is good enough that I could ask for you to send proof that you locked it to my address first, but I know that favors me.  Maybe I send half, you send proof, I send the rest?

I am also wondering about the additional shipping fee zefir said he would charge.  If I can't pay it directly, what happens if it doesn't get paid, chips don't get shipped, and I already paid for them?  I can't find recent information about this, so he may be waiving that based on enough people shipping to a handful of assemblers.