The -01A/B have nothing to do w/ 88A or 88B engines. When the MOCO supersedes any part they add a letter to the suffix. A part can be superseded for any number of reasons. Always try to obtain the latest part revision.
You are probably right but the MoCo's part numbering system leaves a lot to be desired. My rear roadwinder wheel has 2 part numbers stamped into it and a label with a 3rd number and the box has a 4th number (all very different). My SE air cleaner has one part number stamped on it and a different one on the box. Very confusing at the least. So my advice for this guy is to match his part number exactly if possible. BTW, I had 3 dealers tell me the roadwinder wheels you see in my pic would not fit my bike.