AudioFreak's observation is correct, but I'd like to add that when you're using wire that small, the insulation (urethane, enamel, etc.) thickness will begin to be a non-trivial percentage of the thickness of the wire. You may need to fiddle a bit in order to fine tune the inductance. Their wire might have had thicker/thinner insulation than yours.
N.B. I am not saying not to wind you own. Far from it. Just be prepared to scrape a tiny bit of insulation from the wire and test when you're getting close to the stated number of windings. When done testing, paint the scrape with urethane, shellac, etc. (shellac dries very quickly--I've also known people to use fingernail polish, I'll leave the choice of color up to you). Keep notes on any differences in number of turns, etc. so that if you need to wind more inductors, you can turn them out as a production line item in the future.
Since it's a Zobel, does accuracy really matter? 10 turns of 27 gauge, but I can only find 24 gauge here... Would ten turns of 24 gauge do well enough? Or should I order some 27 gauge for the sole purpose of having a foot or two of it?
It's not a Zobel, but it doesn't matter. This value is not critical. You can use #24 without problems. It's a series inductor to avoid problems with capacitive loads/cabling capacitance at high frequencies.