Heres about the cheapest solution to try goto www.marcone.com under contact us there is a 1800 number this is the cheapest appliance parts dealer and the largest in the world .Yes you can replace the ignitors and the leads would be termed as harnesses not quite sure what you are refering to switches that sit on top of gas valves though do you have a site or a picture also send your model number as well and when you goto marcone just get a quoted price from them and then check wolf as well the manufacturer if you have any further questions message me back and please remember when our chat has concluded to rank how this opinion has helped Thanks again Rick

p.s about the most reasonable path would be to take out the ol multimeter and assure that you have the same amount of voltage going to each ignitor in most ovens this is controled by a spark modulator you can also remove each ignitor and do continuity tests on them to assure they are functioning properly as well remember to message me back your model number