It'll be worth checking the old Bob's OLD - cos there's more than one narrow hub standard, including 88mm. Would be nice if it is 73mm, then you can use a nice Brompton hub (if the axle diameter is ok).
The original reason for Brompton's radial front wheels was to use the same length spokes as for the rear wheels. Then they changed to 13G spokes on the rear, losing part of the advantage.