Velocity in Australia , and Sun USA also supply a 349 rim ..
My rim is sourced from Alesa, in Belgium, original parts.
varying sources would give a variety of ERD numbers.

Bike Friday and Brompton may answer your question , via websites
or perhaps SJS, a source of spares in UK.

That's what I would do , in your situation..

I got info from SJS, but sparing shipping 1/3 of the way around the globe,
went thru LBS, and special ordered 30 short 13 ga 150mm spokes to be cut,
[they don't have a bulk spoke cutter, locally]
to replace/rebuild my UK steel shell AW3 after an original spoke broke..
as I expect there may be a cascade of fatigued spoke breakages pending..