Is bulb #1 O2 SENSOR or Check engine? Have you checked the owners manual to see if this on is supposed to come on as a bulb test? The SRS also may come on only briefly. Can you check the bulbs with an ohmmeter? Or did you actually test the sockets for power? You'd need to have your voltmeter attached, THEN turn the key on as these usually only come on briefly after the key is turned.
Bulb 4, the ABS light, that one is fixed now?
I'm just afraid bulbs 1 and 3 could both be bad, as you pointed out, don't want to "ASSume".
Can you maybe swap the bulb out of the ABS socket (since you know it's good) and try it in 1 and 3, but again, remember you need to cycle the key off and on to get the bulb test.
One heads up is that if there were an airbag deplyment or some other SRS problem that a prior owner didn't want to fix, amybe the SRS control unit is disconnected.
With the O2 SENSOR or Check Engine light, that comes from the engine control unit, you may end up checking continuity back to the control unit, and if that's OK, boy oh boy, control unit time, that's why I'd be careful in finding out if that one even comes on as a bulb test, it's possible it doesn't.