primary references for Island One, etc.?

For example, I can't even find the radius of Island One -- Mike Combs' FAQ [1] says it should be 159 m (for a circumference of 1 km), but at that size, the rotation period of 31 sec as described in The High Frontier (p. 59) would produce only 0.67 G. To get the 1 G claimed for Island One, the radius must be about 238 m, but I'd much prefer to see this in an original document rather than inferring it in this way.
__._,___ The funny thing is that I would have sworn it was 1 mile in circumference, not 1 kilometer. But I used The High Frontier as my source when writing my FAQ, so I'm sure that's what it says, at least in one spot. But now I'm thinking thatif we instead assume 1 mile circumference (1.6 km), doesn't that give us the right radius for a period of 32 seconds?