Bearing Question - Need Help

I want to put an '03 or '04 KH Hub (42mm OD) onto a Rowing frame (40mm OD). It appears I need a 20mm ID x 40mm OD. Does anyone know of a bearing to meet this need. UDC does not appear to have them. Thanks in advance.

this might work
http://www.unicycle.com/shopping/shopdisplayproducts.asp?id=2&subcat=15&cat=Adapters&L2=Bearings&L3=Adapters

There are some solutions in this thread: Serious Torker Bearing help.

The best option is to order the bearings used on the Torker DX from any bike shop that carries Torkers. Get a couple pairs because I don’t know how long Torker will be stocking that bearing size. It’s a non-standard size. That should work but I don’t know anyone who has tried it so you’re venturing into new territory.