for the special 1/2-20 bolts holding the front backing plate to the spindle, would it be better to use marsden nuts (locking nuts) or standard nuts with lock washers? I have both but want to use the best, I think marsden was stock.

JB

 

Even though most of us have used lock washers for years they really are ineffective. See this link as but one source example. The key paragraph is:
OEMs haven't used lock washers for years. Your Marsden lock nuts are old school but far better than lock washers if they have not been too rusted, over heated or removed too many times. If you choose to replace them, Stover lock nuts would be a good choice as many OEMs went to those in that type of location.

I have used nyloc nuts everyplace I can but in your case with the nearby brake heat it is probably not a good choice.