Oven burner does not light, pilot light is good, suspect dirty, slightly rusted burner, how do I clean it? This Roper is at least 40yrs old.
It is hard to say what is wrong and what can be done without the complete model number. You can find it on the same name plate where you found the serial number.
If it can not be found, try to post some pictures of the burner and the pilot.
Gene.