Flying a cat 1 approach or a loc approach does NOT depend on your level of automation. With this failure (RA1+2) you can use raw data, HDG/VS, TRK/FPA but of course the easiest is LOC/FPA. Many people here are confused that you now revert to a non precision approach but you are still following a glideslope. So vertical guidance and therefore normal CAT 1 minima as you can fly in you basic c172!