Interesting Brakes

I found that on the driver side I have '77-'78 style shoes and wheel cylinder. and on the passenger side i have the stock '76 shoes and wheel cylinder! I don't know why anyone would ever do this. I can't tell any difference in the half axles and u-joints, can i just get a backing plate for a '77-'78 for the passenger side and complete the mod? I like having the cheaper wheel cyinders! but having half and half is just too weird.