When swapping steering wheels, one usually has to replace the slip rings at least 70% of the time. When you reconnected the airbag, did you hear the connector audibly click? It has to click to make contact. Start by rechecking the connection at the airbag. If the light is still on AND you heard the connector click, then it could be the slip rings.
Before acutally pulling the wheel again, if the SRS light is on try tapping the horn. Sometimes you'll find the spring loaded contacts just need a little push to make connection and tapping the horm douses the lamp. If that doesn't work, then slip rings are in order.
'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.