My dizzy cap was similar to yours in the photos. I was using resistor plugs as "specced" by my local parts store. I eventually realised that they should be non resistor, since then my dist cap is a lot cleaner (I check it and clean it every now and again) and the car runs a lot better.
The old cap can be cleaned and used as a spare, use needle files and fine emery or a mini die grinder to buff up the brass terminals. Yeah the clearances aren't the same but its a spare!