The 1990MY sedan W124 uses the 3.0L M103 177hp SOHC engine, and it's head gasket failure rate seems much lower then the DOHC M104 engine.
If you are having the car inspected by a dealer, forget Hyatt's service dept. Go to Lonestar.
Blinking SRS lights are most commonly caused by failing steering wheel contact points. Easy to repair.
1998 C230 "Black Betty"