This guy posted on the Rennlist 930 board a couple of weeks ago. He says it runs $300 to clean it up and make it adjustable:
Hello,
I offer the service of making your 930 WUR fully adjustable. I rebuild the unit and modify it, adding adjustment features for the cold, warm, and full-throttle enrichment control pressures. I also provide a means of adjusting the full-throttle enrichment threshold (the point at which the WUR enriches based upon manifold pressure). All of the adjustment hardware used is high quality stainless steel for longevity without rust or corrosion. Before shipping it back to you, I can set your WUR to exact factory specs or whatever settings you desire. If you provide me your engine details, I can offer my suggestions for custom control pressure settings and set the unit accordingly. A 12 page color instruction sheet is included with each unit that details each adjustment feature and documents your particular WUR settings.
Please contact me for more information.
Brian Leask
bleask@cox.net