Hi
I am not aware it has been rebuilt in the past.Is there a fuse within the SRS module itself ? I dont know much about it hence I'm using a auto electrician .My car has been modified in the past in that it's got a after market quick release steering wheel no air bags and after market seats so it could be something has become disconnected as the light has only just come on . I think the electrician wanted leads before he started getting to involved taking it all apart.
Hope that make sence .
Regards
Mark