I used a piece of copper wire out of electrical chord and a ton of air last time.  Think I'll stick with that.  Of course, I have a ton of guitar strings lying around, which would have been easier, but they seemed a little harsh to me.  
I have a line on some OEM replacement gaskets and o-rings.
Delta: at this link, the kits are listed at the top of the page (01), but there are 2 of them listed as the same replacement number (16010-323-315), but it shows them replacing 2 different originals.  Not sure what the difference would be.  I emailed the site - but they have not gotten back to me.  Any idea?
Thanks