Non of the salvage yards in your area have any air bag steering wheels? You could try M&M Salvage 1-800-429-7278 (Nationwide Watts line, company in Fontana, CA), ask for Chad, tell him I referred you. They have several airbag equipped MB vehicles, and should be able to ship (they don't ship glass though).
You might have to replace the slip rings when doing a wheel change (I did), but it is not a difficult job, very simple in fact. Parts are about $74.00 at Fastlane and take about 30 minutes to install.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.